#NEWLINE# @ property #NEWLINE# def required_fields( self ) : #NEWLINE# #INDENT# ' Specifies a comma-separated list of required field names.\n\n            This list is computed as the union of the set of fieldnames and\n            fieldname-valued options given as argument to this command.\n\n            ' #NEWLINE# fieldnames = set ( self . command . fieldnames ) #NEWLINE# for ( name , option ) in self . command . options . iteritems ( ) : #NEWLINE# #INDENT# if isinstance ( self . validator , Fieldname ) : #NEWLINE# #INDENT# value = option . value #NEWLINE# if ( value is not None ) : #NEWLINE# #INDENT# fieldnames . add ( value ) #NEWLINE# #UNINDENT# #UNINDENT# #UNINDENT# text = ',' . join ( fieldnames ) #NEWLINE# return text