neulab/docprompting-conala huggingface dataset:
classBracketAB(widthA=1.0, lengthA=0.2, angleA=0, widthB=1.0, lengthB=0.2, angleB=0)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with outward square brackets at both ends.  Parameters 
 
widthA, widthBfloat, default: 1.0


Width of the bracket.  
lengthA, lengthBfloat, default: 0.2


Length of the bracket.  
angleA, angleBfloat, default: 0 degrees


Orientation of the bracket, as a counterclockwise angle. 0 degrees means perpendicular to the line.       arrow=']-['
classBracketB(widthB=1.0, lengthB=0.2, angleB=0)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with an outward square bracket at its end.  Parameters 
 
widthBfloat, default: 1.0


Width of the bracket.  
lengthBfloat, default: 0.2


Length of the bracket.  
angleBfloat, default: 0 degrees


Orientation of the bracket, as a counterclockwise angle. 0 degrees means perpendicular to the line.       arrow='-['
classBracketCurve(widthA=1.0, lengthA=0.2, angleA=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with an outward square bracket at its start and a head at the end.  Parameters 
 
widthAfloat, default: 1.0


Width of the bracket.  
lengthAfloat, default: 0.2


Length of the bracket.  
angleAfloat, default: 0 degrees


Orientation of the bracket, as a counterclockwise angle. 0 degrees means perpendicular to the line.       arrow=']->'
classCurve[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve A simple curve without any arrow head.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head, relative to mutation_scale.  
head_widthfloat, default: 0.2


Width of the arrow head, relative to mutation_scale.  
widthAfloat, default: 1.0


Width of the bracket at the beginning of the arrow  
widthBfloat, default: 1.0


Width of the bracket at the end of the arrow  
lengthAfloat, default: 0.2


Length of the bracket at the beginning of the arrow  
lengthBfloat, default: 0.2


Length of the bracket at the end of the arrow  
angleAfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
angleBfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
scaleAfloat, default mutation_size


The mutation_size for the beginning bracket  
scaleBfloat, default mutation_size


The mutation_size for the end bracket
classCurveA(head_length=0.4, head_width=0.2, widthA=1.0, widthB=1.0, lengthA=0.2, lengthB=0.2, angleA=0, angleB=0, scaleA=None, scaleB=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with a head at its begin point.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head, relative to mutation_scale.  
head_widthfloat, default: 0.2


Width of the arrow head, relative to mutation_scale.  
widthAfloat, default: 1.0


Width of the bracket at the beginning of the arrow  
widthBfloat, default: 1.0


Width of the bracket at the end of the arrow  
lengthAfloat, default: 0.2


Length of the bracket at the beginning of the arrow  
lengthBfloat, default: 0.2


Length of the bracket at the end of the arrow  
angleAfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
angleBfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
scaleAfloat, default mutation_size


The mutation_size for the beginning bracket  
scaleBfloat, default mutation_size


The mutation_size for the end bracket       arrow='<-'
classCurveAB(head_length=0.4, head_width=0.2, widthA=1.0, widthB=1.0, lengthA=0.2, lengthB=0.2, angleA=0, angleB=0, scaleA=None, scaleB=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with heads both at the begin and the end point.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head, relative to mutation_scale.  
head_widthfloat, default: 0.2


Width of the arrow head, relative to mutation_scale.  
widthAfloat, default: 1.0


Width of the bracket at the beginning of the arrow  
widthBfloat, default: 1.0


Width of the bracket at the end of the arrow  
lengthAfloat, default: 0.2


Length of the bracket at the beginning of the arrow  
lengthBfloat, default: 0.2


Length of the bracket at the end of the arrow  
angleAfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
angleBfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
scaleAfloat, default mutation_size


The mutation_size for the beginning bracket  
scaleBfloat, default mutation_size


The mutation_size for the end bracket       arrow='<->'
classCurveB(head_length=0.4, head_width=0.2, widthA=1.0, widthB=1.0, lengthA=0.2, lengthB=0.2, angleA=0, angleB=0, scaleA=None, scaleB=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with a head at its end point.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head, relative to mutation_scale.  
head_widthfloat, default: 0.2


Width of the arrow head, relative to mutation_scale.  
widthAfloat, default: 1.0


Width of the bracket at the beginning of the arrow  
widthBfloat, default: 1.0


Width of the bracket at the end of the arrow  
lengthAfloat, default: 0.2


Length of the bracket at the beginning of the arrow  
lengthBfloat, default: 0.2


Length of the bracket at the end of the arrow  
angleAfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
angleBfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
scaleAfloat, default mutation_size


The mutation_size for the beginning bracket  
scaleBfloat, default mutation_size


The mutation_size for the end bracket       arrow='->'
classCurveBracket(widthB=1.0, lengthB=0.2, angleB=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with an outward square bracket at its end and a head at the start.  Parameters 
 
widthBfloat, default: 1.0


Width of the bracket.  
lengthBfloat, default: 0.2


Length of the bracket.  
angleBfloat, default: 0 degrees


Orientation of the bracket, as a counterclockwise angle. 0 degrees means perpendicular to the line.       arrow='<-['
classCurveFilledA(head_length=0.4, head_width=0.2, widthA=1.0, widthB=1.0, lengthA=0.2, lengthB=0.2, angleA=0, angleB=0, scaleA=None, scaleB=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with filled triangle head at the begin.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head, relative to mutation_scale.  
head_widthfloat, default: 0.2


Width of the arrow head, relative to mutation_scale.  
widthAfloat, default: 1.0


Width of the bracket at the beginning of the arrow  
widthBfloat, default: 1.0


Width of the bracket at the end of the arrow  
lengthAfloat, default: 0.2


Length of the bracket at the beginning of the arrow  
lengthBfloat, default: 0.2


Length of the bracket at the end of the arrow  
angleAfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
angleBfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
scaleAfloat, default mutation_size


The mutation_size for the beginning bracket  
scaleBfloat, default mutation_size


The mutation_size for the end bracket       arrow='<|-'
classCurveFilledAB(head_length=0.4, head_width=0.2, widthA=1.0, widthB=1.0, lengthA=0.2, lengthB=0.2, angleA=0, angleB=0, scaleA=None, scaleB=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with filled triangle heads at both ends.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head, relative to mutation_scale.  
head_widthfloat, default: 0.2


Width of the arrow head, relative to mutation_scale.  
widthAfloat, default: 1.0


Width of the bracket at the beginning of the arrow  
widthBfloat, default: 1.0


Width of the bracket at the end of the arrow  
lengthAfloat, default: 0.2


Length of the bracket at the beginning of the arrow  
lengthBfloat, default: 0.2


Length of the bracket at the end of the arrow  
angleAfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
angleBfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
scaleAfloat, default mutation_size


The mutation_size for the beginning bracket  
scaleBfloat, default mutation_size


The mutation_size for the end bracket       arrow='<|-|>'
classCurveFilledB(head_length=0.4, head_width=0.2, widthA=1.0, widthB=1.0, lengthA=0.2, lengthB=0.2, angleA=0, angleB=0, scaleA=None, scaleB=None)[source]
 
Bases: matplotlib.patches.ArrowStyle._Curve An arrow with filled triangle head at the end.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head, relative to mutation_scale.  
head_widthfloat, default: 0.2


Width of the arrow head, relative to mutation_scale.  
widthAfloat, default: 1.0


Width of the bracket at the beginning of the arrow  
widthBfloat, default: 1.0


Width of the bracket at the end of the arrow  
lengthAfloat, default: 0.2


Length of the bracket at the beginning of the arrow  
lengthBfloat, default: 0.2


Length of the bracket at the end of the arrow  
angleAfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
angleBfloat, default 0


Orientation of the bracket at the beginning, as a counterclockwise angle. 0 degrees means perpendicular to the line.  
scaleAfloat, default mutation_size


The mutation_size for the beginning bracket  
scaleBfloat, default mutation_size


The mutation_size for the end bracket       arrow='-|>'
classFancy(head_length=0.4, head_width=0.4, tail_width=0.4)[source]
 
Bases: matplotlib.patches.ArrowStyle._Base A fancy arrow. Only works with a quadratic Bezier curve.  Parameters 
 
head_lengthfloat, default: 0.4


Length of the arrow head.  
head_widthfloat, default: 0.4


Width of the arrow head.  
tail_widthfloat, default: 0.4


Width of the arrow tail.       transmute(path, mutation_size, linewidth)[source]
 
The transmute method is the very core of the ArrowStyle class and must be overridden in the subclasses. It receives the path object along which the arrow will be drawn, and the mutation_size, with which the arrow head etc. will be scaled. The linewidth may be used to adjust the path so that it does not pass beyond the given points. It returns a tuple of a Path instance and a boolean. The boolean value indicate whether the path can be filled or not. The return value can also be a list of paths and list of booleans of a same length.
transmute(path, mutation_size, linewidth)[source]
 
The transmute method is the very core of the ArrowStyle class and must be overridden in the subclasses. It receives the path object along which the arrow will be drawn, and the mutation_size, with which the arrow head etc. will be scaled. The linewidth may be used to adjust the path so that it does not pass beyond the given points. It returns a tuple of a Path instance and a boolean. The boolean value indicate whether the path can be filled or not. The return value can also be a list of paths and list of booleans of a same length.
classSimple(head_length=0.5, head_width=0.5, tail_width=0.2)[source]
 
Bases: matplotlib.patches.ArrowStyle._Base A simple arrow. Only works with a quadratic Bezier curve.  Parameters 
 
head_lengthfloat, default: 0.5


Length of the arrow head.  
head_widthfloat, default: 0.5


Width of the arrow head.  
tail_widthfloat, default: 0.2


Width of the arrow tail.       transmute(path, mutation_size, linewidth)[source]
 
The transmute method is the very core of the ArrowStyle class and must be overridden in the subclasses. It receives the path object along which the arrow will be drawn, and the mutation_size, with which the arrow head etc. will be scaled. The linewidth may be used to adjust the path so that it does not pass beyond the given points. It returns a tuple of a Path instance and a boolean. The boolean value indicate whether the path can be filled or not. The return value can also be a list of paths and list of booleans of a same length.
classWedge(tail_width=0.3, shrink_factor=0.5)[source]
 
Bases: matplotlib.patches.ArrowStyle._Base Wedge(?) shape. Only works with a quadratic Bezier curve. The begin point has a width of the tail_width and the end point has a width of 0. At the middle, the width is shrink_factor*tail_width.  Parameters 
 
tail_widthfloat, default: 0.3


Width of the tail.  
shrink_factorfloat, default: 0.5


Fraction of the arrow width at the middle point.       transmute(path, mutation_size, linewidth)[source]
 
The transmute method is the very core of the ArrowStyle class and must be overridden in the subclasses. It receives the path object along which the arrow will be drawn, and the mutation_size, with which the arrow head etc. will be scaled. The linewidth may be used to adjust the path so that it does not pass beyond the given points. It returns a tuple of a Path instance and a boolean. The boolean value indicate whether the path can be filled or not. The return value can also be a list of paths and list of booleans of a same length.
matplotlib.patches.bbox_artist   matplotlib.patches.bbox_artist(artist, renderer, props=None, fill=True)[source]
 
A debug function to draw a rectangle around the bounding box returned by an artist's Artist.get_window_extent to test whether the artist is returning the correct bbox. props is a dict of rectangle props with the additional property 'pad' that sets the padding around the bbox in points.
classCircle(pad=0.3)[source]
 
Bases: matplotlib.patches.BoxStyle._Base A circular box.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
__call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classDArrow(pad=0.3)[source]
 
Bases: matplotlib.patches.BoxStyle._Base A box in the shape of a two-way arrow.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classLArrow(pad=0.3)[source]
 
Bases: matplotlib.patches.BoxStyle._Base A box in the shape of a left-pointing arrow.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classRArrow(pad=0.3)[source]
 
Bases: matplotlib.patches.BoxStyle.LArrow A box in the shape of a right-pointing arrow.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classRound(pad=0.3, rounding_size=None)[source]
 
Bases: matplotlib.patches.BoxStyle._Base A box with round corners.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.  
rounding_sizefloat, default: pad


Radius of the corners.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classRound4(pad=0.3, rounding_size=None)[source]
 
Bases: matplotlib.patches.BoxStyle._Base A box with rounded edges.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.  
rounding_sizefloat, default: pad/2


Rounding of edges.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classRoundtooth(pad=0.3, tooth_size=None)[source]
 
Bases: matplotlib.patches.BoxStyle.Sawtooth A box with a rounded sawtooth outline.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.  
tooth_sizefloat, default: pad/2


Size of the sawtooth.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classSawtooth(pad=0.3, tooth_size=None)[source]
 
Bases: matplotlib.patches.BoxStyle._Base A box with a sawtooth outline.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.  
tooth_sizefloat, default: pad/2


Size of the sawtooth.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
classSquare(pad=0.3)[source]
 
Bases: matplotlib.patches.BoxStyle._Base A square box.  Parameters 
 
padfloat, default: 0.3


The amount of padding around the original box.       __call__(x0, y0, width, height, mutation_size, mutation_aspect=<deprecated parameter>)[source]
 
Given the location and size of the box, return the path of the box around it.  Parameters 
 
x0, y0, width, heightfloat


Location and size of the box.  
mutation_sizefloat


A reference scale for the mutation.    Returns 
 Path
set(*, agg_filter=<UNSET>, alpha=<UNSET>, angle=<UNSET>, animated=<UNSET>, antialiased=<UNSET>, capstyle=<UNSET>, center=<UNSET>, clip_box=<UNSET>, clip_on=<UNSET>, clip_path=<UNSET>, color=<UNSET>, edgecolor=<UNSET>, facecolor=<UNSET>, fill=<UNSET>, gid=<UNSET>, hatch=<UNSET>, height=<UNSET>, in_layout=<UNSET>, joinstyle=<UNSET>, label=<UNSET>, linestyle=<UNSET>, linewidth=<UNSET>, path_effects=<UNSET>, picker=<UNSET>, radius=<UNSET>, rasterized=<UNSET>, sketch_params=<UNSET>, snap=<UNSET>, transform=<UNSET>, url=<UNSET>, visible=<UNSET>, width=<UNSET>, zorder=<UNSET>)[source]
 
Set multiple properties at once. Supported properties are   
Property Description   
agg_filter a filter function, which takes a (m, n, 3) float array and a dpi value, and returns a (m, n, 3) array  
alpha scalar or None  
angle float  
animated bool  
antialiased or aa bool or None  
capstyle CapStyle or {'butt', 'projecting', 'round'}  
center (float, float)  
clip_box Bbox  
clip_on bool  
clip_path Patch or (Path, Transform) or None  
color color  
edgecolor or ec color or None  
facecolor or fc color or None  
figure Figure  
fill bool  
gid str  
hatch {'/', '\', '|', '-', '+', 'x', 'o', 'O', '.', '*'}  
height float  
in_layout bool  
joinstyle JoinStyle or {'miter', 'round', 'bevel'}  
label object  
linestyle or ls {'-', '--', '-.', ':', '', (offset, on-off-seq), ...}  
linewidth or lw float or None  
path_effects AbstractPathEffect  
picker None or bool or float or callable  
radius float  
rasterized bool  
sketch_params (scale: float, length: float, randomness: float)  
snap bool or None  
transform Transform  
url str  
visible bool  
width float  
zorder float
set_radius(radius)[source]
 
Set the radius of the circle.  Parameters 
 
radiusfloat
matplotlib.patches.CirclePolygon   classmatplotlib.patches.CirclePolygon(xy, radius=5, resolution=20, **kwargs)[source]
 
Bases: matplotlib.patches.RegularPolygon A polygon-approximation of a circle patch. Create a circle at xy = (x, y) with given radius. This circle is approximated by a regular polygon with resolution sides. For a smoother circle drawn with splines, see Circle. Valid keyword arguments are:   
Property Description   
agg_filter a filter function, which takes a (m, n, 3) float array and a dpi value, and returns a (m, n, 3) array  
alpha unknown  
animated bool  
antialiased or aa bool or None  
capstyle CapStyle or {'butt', 'projecting', 'round'}  
clip_box Bbox  
clip_on bool  
clip_path Patch or (Path, Transform) or None  
color color  
edgecolor or ec color or None  
facecolor or fc color or None  
figure Figure  
fill bool  
gid str  
hatch {'/', '\', '|', '-', '+', 'x', 'o', 'O', '.', '*'}  
in_layout bool  
joinstyle JoinStyle or {'miter', 'round', 'bevel'}  
label object  
linestyle or ls {'-', '--', '-.', ':', '', (offset, on-off-seq), ...}  
linewidth or lw float or None  
path_effects AbstractPathEffect  
picker None or bool or float or callable  
rasterized bool  
sketch_params (scale: float, length: float, randomness: float)  
snap bool or None  
transform Transform  
url str  
visible bool  
zorder float     set(*, agg_filter=<UNSET>, alpha=<UNSET>, animated=<UNSET>, antialiased=<UNSET>, capstyle=<UNSET>, clip_box=<UNSET>, clip_on=<UNSET>, clip_path=<UNSET>, color=<UNSET>, edgecolor=<UNSET>, facecolor=<UNSET>, fill=<UNSET>, gid=<UNSET>, hatch=<UNSET>, in_layout=<UNSET>, joinstyle=<UNSET>, label=<UNSET>, linestyle=<UNSET>, linewidth=<UNSET>, path_effects=<UNSET>, picker=<UNSET>, rasterized=<UNSET>, sketch_params=<UNSET>, snap=<UNSET>, transform=<UNSET>, url=<UNSET>, visible=<UNSET>, zorder=<UNSET>)[source]
 
Set multiple properties at once. Supported properties are   
Property Description   
agg_filter a filter function, which takes a (m, n, 3) float array and a dpi value, and returns a (m, n, 3) array  
alpha scalar or None  
animated bool  
antialiased or aa bool or None  
capstyle CapStyle or {'butt', 'projecting', 'round'}  
clip_box Bbox  
clip_on bool  
clip_path Patch or (Path, Transform) or None  
color color  
edgecolor or ec color or None  
facecolor or fc color or None  
figure Figure  
fill bool  
gid str  
hatch {'/', '\', '|', '-', '+', 'x', 'o', 'O', '.', '*'}  
in_layout bool  
joinstyle JoinStyle or {'miter', 'round', 'bevel'}  
label object  
linestyle or ls {'-', '--', '-.', ':', '', (offset, on-off-seq), ...}  
linewidth or lw float or None  
path_effects AbstractPathEffect  
picker None or bool or float or callable  
rasterized bool  
sketch_params (scale: float, length: float, randomness: float)  
snap bool or None  
transform Transform  
url str  
visible bool  
zorder float
get_annotation_clip()[source]
 
Return the clipping behavior. See set_annotation_clip for the meaning of the return value.