user: Describe Bpy.Types.Greasepencillayermask from the Blender manual or Python API, including usage steps and snippets.

assistant: Mesh(GeometryNode) GeometryNodeCurveToPoints(GeometryNode) GeometryNodeCurvesToGreasePencil(GeometryNode) GeometryNodeCustomGroup(GeometryNode) GeometryNodeDeformCurvesOnSurface(GeometryNode) GeometryNodeDeleteGeometry(GeometryNode) GeometryNodeDistributePointsInGrid(GeometryNode) GeometryNodeDistributePointsInVolume(GeometryNode) GeometryNodeDistributePointsOnFaces(GeometryNode) GeometryNodeDualMesh(GeometryNode) GeometryNodeDuplicateElements(GeometryNode) GeometryNodeEdgePathsToCurves(GeometryNode) GeometryNodeEdgePathsToSelection(GeometryNode) GeometryNodeEdgesOfCorner(GeometryNode) GeometryNodeEdgesOfVertex(GeometryNode) GeometryNodeEdgesToFaceGroups(GeometryNode) GeometryNodeExtrudeMesh(GeometryNode) GeometryNodeFaceOfCorner(GeometryNode) GeometryNodeFieldAtIndex(GeometryNode) GeometryNodeFieldAverage(GeometryNode) GeometryNodeFieldMinAndMax(GeometryNode) GeometryNodeFieldOnDomain(GeometryNode) GeometryNodeFieldToGrid(GeometryNode) GeometryNodeFieldToGridItem(bpy_struct) GeometryNodeFieldToGridItems(bpy_struct) GeometryNodeFieldVariance(GeometryNode) GeometryNodeFillCurve(GeometryNode) GeometryNodeFilletCurve(GeometryNode) GeometryNodeFlipFaces(GeometryNode) GeometryNodeForeachGeometryElementInput(GeometryNode) GeometryNodeForeachGeometryElementOutput(GeometryNode) GeometryNodeGeometryToInstance(GeometryNode) GeometryNodeGetNamedGrid(GeometryNode) GeometryNodeGizmoDial(GeometryNode) GeometryNodeGizmoLinear(GeometryNode) GeometryNodeGizmoTransform(GeometryNode) GeometryNodeGreasePencilToCurves(GeometryNode) GeometryNodeGridAdvect(GeometryNode) GeometryNodeGridCurl(GeometryNode) GeometryNodeGridDivergence(GeometryNode) GeometryNodeGridGradient(GeometryNode) GeometryNodeGridInfo(GeometryNode) GeometryNodeGridLaplacian(GeometryNode) GeometryNodeGridPrune(GeometryNode) GeometryNodeGridToMesh(GeometryNode) GeometryNodeGridVoxelize(GeometryNode) GeometryNodeGroup(GeometryNode) GeometryNodeImageInfo(GeometryNode) GeometryNodeImageTexture(GeometryNode) GeometryNodeImportCSV(GeometryNode) GeometryNodeImportOBJ(GeometryNode) GeometryNodeImportPLY(GeometryNode) GeometryNodeImportSTL(GeometryNode) GeometryNodeImportText(GeometryNode) GeometryNodeImportVDB(GeometryNode) GeometryNodeIndexOfNearest(GeometryNode) GeometryNodeIndexSwitch(GeometryNode) GeometryNodeInputActiveCamera(GeometryNode) GeometryNodeInputCollection(GeometryNode) GeometryNodeInputCurveHandlePositions(GeometryNode) GeometryNodeInputCurveTilt(GeometryNode) GeometryNodeInputEdgeSmooth(GeometryNode) GeometryNodeInputID(GeometryNode) GeometryNodeInputImage(GeometryNode) GeometryNodeInputIndex(GeometryNode) GeometryNodeInputInstanceBounds(GeometryNode) GeometryNodeInputInstanceRotation(GeometryNode) GeometryNodeInputInstanceScale(GeometryNode) GeometryNodeInputMaterial(GeometryNode) GeometryNodeInputMaterialIndex(GeometryNode) GeometryNodeInputMeshEdgeAngle(GeometryNode) GeometryNodeInputMeshEdgeNeighbors(GeometryNode) GeometryNodeInputMeshEdgeVertices(GeometryNode) GeometryNodeInputMeshFaceArea(GeometryNode) GeometryNodeInputMeshFaceIsPlanar(GeometryNode) GeometryNodeInputMeshFaceNeighbors(GeometryNode) GeometryNodeInputMeshIsland(GeometryNode) GeometryNodeInputMeshVertexNeighbors(GeometryNode) GeometryNodeInputNamedAttribute(GeometryNode) GeometryNodeInputNamedLayerSelection(GeometryNode) GeometryNodeInputNormal(GeometryNode) GeometryNodeInputObject(GeometryNode) GeometryNodeInputPosition(GeometryNode) GeometryNodeInputRadius(GeometryNode) GeometryNodeInputSceneTime(GeometryNode) GeometryNodeInputShadeSmooth(GeometryNode) GeometryNodeInputShortestEdgePaths(GeometryNode) GeometryNodeInputSplineCyclic(GeometryNode) GeometryNodeInputSplineResolution(GeometryNode) GeometryNodeInputTangent(GeometryNode) GeometryNodeInputVoxelIndex(GeometryNode) GeometryNodeInstanceOnPoints(GeometryNode) GeometryNodeInstanceTransform(GeometryNode) GeometryNodeInstancesToPoints(GeometryNode) GeometryNodeInterpolateCurves(GeometryNode) GeometryNodeIsViewport(GeometryNode) GeometryNodeJoinGeometry(GeometryNode) GeometryNodeList(GeometryNode) GeometryNodeListGetItem(GeometryNode) GeometryNodeListLength(GeometryNode) GeometryNodeMaterialSelection(GeometryNode) GeometryNodeMenuSwitch(GeometryNode) GeometryNodeMergeByDistance(GeometryNode) GeometryNodeMergeLayers(GeometryNode) GeometryNodeMeshBoolean(GeometryNode) GeometryNodeMeshCircle(GeometryNode) GeometryNodeMeshCone(GeometryNode) GeometryNodeMeshCube(GeometryNode) GeometryNodeMeshCylinder(GeometryNode) GeometryNodeMeshFaceSetBoundaries(GeometryNode) GeometryNodeMeshGrid(GeometryNode) GeometryNodeMeshIcoSphere(GeometryNode) GeometryNodeMeshLine(GeometryNode) GeometryNodeMeshToCurve(GeometryNode) GeometryNodeMeshToDensityGrid(GeometryNode) GeometryNodeMeshToPoints(GeometryNode) GeometryNodeMeshToSDFGrid(GeometryNode) GeometryNodeMeshToVolume(GeometryNode) GeometryNodeMeshUVSphere(GeometryNode) GeometryNodeObjectInfo(GeometryNode) GeometryNodeOffsetCornerInFace(GeometryNode) GeometryNodeOffsetPointInCurve(GeometryNode) GeometryNodePoints(GeometryNode) GeometryNodePointsOfCurve(GeometryNode) GeometryNodePointsToCurves(GeometryNode) GeometryNodePointsToSDFGrid(GeometryNode) GeometryNodePointsToVertices(GeometryNode) GeometryNodePointsToVolume(GeometryNode) GeometryNodeProximity(GeometryNode) GeometryNodeRaycast(GeometryNode) GeometryNodeRealizeInstances(GeometryNode) GeometryNodeRemoveAttribute(GeometryNode) GeometryNodeRepeatInput(GeometryNode) GeometryNodeRepeatOutput(GeometryNode) GeometryNodeReplaceMaterial(GeometryNode) GeometryNodeResampleCurve(GeometryNode) GeometryNodeReverseCurve(GeometryNode) GeometryNodeRotateInstances(GeometryNode) GeometryNodeSDFGridBoolean(GeometryNode) GeometryNodeSDFGridFillet(GeometryNode) GeometryNodeSDFGridLaplacian(GeometryNode) GeometryNodeSDFGridMean(GeometryNode) GeometryNodeSDFGridMeanCurvature(GeometryNode) GeometryNodeSDFGridMedian(GeometryNode) GeometryNodeSDFGridOffset(GeometryNode) GeometryNodeSampleCurve(GeometryNode) GeometryNodeSampleGrid(GeometryNode) GeometryNodeSampleGridIndex(GeometryNode) GeometryNodeSampleIndex(GeometryNode) GeometryNodeSampleNearest(GeometryNode) GeometryNodeSampleNearestSurface(GeometryNode) GeometryNodeSampleUVSurface(GeometryNode) GeometryNodeScaleElements(GeometryNode) GeometryNodeScaleInstances(GeometryNode) GeometryNodeSelfObject(GeometryNode) GeometryNodeSeparateComponents(GeometryNode) GeometryNodeSeparateGeometry(GeometryNode) GeometryNodeSetCurveHandlePositions(GeometryNode) GeometryNodeSetCurveNormal(GeometryNode) GeometryNodeSetCurveRadius(GeometryNode) GeometryNodeSetCurveTilt(GeometryNode) GeometryNodeSetGeometryName(GeometryNode) GeometryNodeSetGreasePencilColor(GeometryNode) GeometryNodeSetGreasePencilDepth(GeometryNode) GeometryNodeSetGreasePencilSoftness(GeometryNode) GeometryNodeSetGridBackground(GeometryNode) GeometryNodeSetGridTransform(GeometryNode) GeometryNodeSetID(GeometryNode) GeometryNodeSetInstanceTransform(GeometryNode) GeometryNodeSetMaterial(GeometryNode) GeometryNodeSetMaterialIndex(GeometryNode) GeometryNodeSetMeshNormal(GeometryNode) GeometryNodeSetPointRadius(GeometryNode) GeometryNodeSetPosition(GeometryNode) GeometryNodeSetShadeSmooth(GeometryNode) GeometryNodeSetSplineCyclic(GeometryNode) GeometryNodeSetSplineResolution(GeometryNode) GeometryNodeSimulationInput(GeometryNode) GeometryNodeSimulationOutput(GeometryNode) GeometryNodeSortElements(GeometryNode) GeometryNodeSplineLength(GeometryNode) GeometryNodeSplineParameter(GeometryNode) GeometryNodeSplitEdges(GeometryNode) GeometryNodeSplitToInstances(GeometryNode) GeometryNodeStoreNamedAttribute(GeometryNode) GeometryNodeStoreNamedGrid(GeometryNode) GeometryNodeStringJoin(GeometryNode) GeometryNodeStringToCurves(GeometryNode) GeometryNodeSubdivideCurve(GeometryNode) GeometryNodeSubdivideMesh(GeometryNode) GeometryNodeSubdivisionSurface(GeometryNode) GeometryNodeSwitch(GeometryNode) GeometryNodeTool3DCursor(GeometryNode) GeometryNodeToolActiveElement(GeometryNode) GeometryNodeToolFaceSet(GeometryNode) GeometryNodeToolMousePosition(GeometryNode) GeometryNodeToolSelection(GeometryNode) GeometryNodeToolSetFaceSet(GeometryNode) GeometryNodeToolSetSelection(GeometryNode) GeometryNodeTransform(GeometryNode) GeometryNodeTranslateInstances(GeometryNode) GeometryNodeTree(NodeTree) GeometryNodeTriangulate(GeometryNode) GeometryNodeTrimCurve(GeometryNode) GeometryNodeUVPackIslands(GeometryNode) GeometryNodeUVTangent(GeometryNode) GeometryNodeUVUnwrap(GeometryNode) GeometryNodeVertexOfCorner(GeometryNode) GeometryNodeViewer(GeometryNode) GeometryNodeViewportTransform(GeometryNode) GeometryNodeVolumeCube(GeometryNode) GeometryNodeVolumeToMesh(GeometryNode) GeometryNodeWarning(GeometryNode) GeometrySet Gizmo(bpy_struct) GizmoGroup(bpy_struct) GizmoGroupProperties(bpy_struct) GizmoProperties(bpy_struct) Gizmos(bpy_struct) GlowStrip(EffectStrip) GpPaint(Paint) GpSculptPaint(Paint) GpVertexPaint(Paint) GpWeightPaint(Paint) GreasePencil(ID) GreasePencilArmatureModifier(Modifier) GreasePencilArrayModifier(Modifier) GreasePencilBuildModifier(Modifier) GreasePencilColorModifier(Modifier) GreasePencilDashModifierData(Modifier) GreasePencilDashModifierSegment(bpy_struct) GreasePencilDrawing(bpy_struct) GreasePencilEnvelopeModifier(Modifier) GreasePencilFrame(bpy_struct) GreasePencilFrames(bpy_struct) GreasePencilHookModifier(Modifier) GreasePencilLatticeModifier(Modifier) GreasePencilLayer(GreasePencilTreeNode) GreasePencilLayerGroup(GreasePencilTreeNode) GreasePencilLayerMask(bpy_struct) GreasePencilLayerMasks(bpy_struct) GreasePencilLengthModifier(Modifier) GreasePencilLineartModifier(Modifier) GreasePencilMirrorModifier(Modifier) GreasePencilMultiplyModifier(Modifier) GreasePencilNoiseModifier(Modifier) GreasePencilOffsetModifier(Modifier) GreasePencilOpacityModifier(Modifier) GreasePencilOutlineModifier(Modifier) GreasePencilShrinkwrapModifier(Modifier) GreasePencilSimplifyModifier(Modifier) GreasePencilSmoothModifier(Modifier) GreasePencilSubdivModifier(Modifier) GreasePencilTextureModifier(Modifier) GreasePencilThickModifierData(Modifier) GreasePencilTimeModifier(Modifier) GreasePencilTimeModifierSegment(bpy_struct) GreasePencilTintModifier(Modifier) GreasePencilTreeNode(bpy_struct) GreasePencilWeightAngleModifier(Modifier) GreasePencilWeightProximityModifier(Modifier) GreasePencilv3LayerGroup(bpy_struct) GreasePencilv3Layers(bpy_struct) GroupNodeViewerPathElem(ViewerPathElem) Header(bpy_struct) Histogram(bpy_struct) HookModifier(Modifier) HueCorrectModifier(StripModifier) HydraRenderEngine(RenderEngine) ID(bpy_struct) IDMaterials(bpy_struct) IDOverrideLibrary(bpy_struct) IDOverrideLibraryProperties(bpy_struct) IDOverrideLibraryProperty(bpy_struct) IDOverrideLibraryPropertyOperation(bpy_struct) IDOverrideLibraryPropertyOperations(bpy_struct) IDPropertyWrapPtr(bpy_struct) IDViewerPathElem(ViewerPathElem) IKParam(bpy_struct) IMAGE_AST_brush_paint(AssetShelf) IMAGE_FH_drop_handler(FileHandler) IMAGE_UL_render_slots(UIList) IMAGE_UL_udim_tiles(UIList) IO_FH_gltf2(FileHandler) IO_FH_svg_as_curves(FileHandler) Image(ID) ImageFormatSettings(bpy_struct) ImagePackedFile(bpy_struct) ImagePaint(Paint) ImagePreview(bpy_struct) ImageStrip(Strip) ImageTexture(Texture) ImageUser(bpy_struct) IndexSwitchItem(bpy_struct) InlineShaderNodes Int2Attribute(Attribute) Int2AttributeValue(bpy_struct) IntAttribute(Attribute) IntAttributeValue(bpy_struct) IntProperty(Property) Itasc(IKParam) Key(ID) KeyConfig(bpy_struct) KeyConfigPreferences(bpy_struct) KeyConfigurations(bpy_struct) KeyMap(bpy_struct) KeyMapItem(bpy_struct) KeyMapItems(bpy_struct) KeyMaps(bpy_struct) Keyframe(bpy_struct) KeyingSet(bpy_struct) KeyingSetInfo(bpy_struct) KeyingSetPath(bpy_struct) KeyingSetPaths(bpy_struct) KeyingSets(bpy_struct) KeyingSetsAll(bpy_struct) KinematicConstraint(Constraint) LaplacianDeformModifier(Modifier) LaplacianSmoothModifier(Modifier) Lattice(ID) LatticeModifier(Modifier) LatticePoint(bpy_struct) LayerCollection(bpy_struct) LayerObjects(bpy_struct) LayoutPanelState(bpy_struct) Library(ID) LibraryWeakReference(bpy_struct) Light(ID) LightProbe(ID) LightProbePlane(LightProbe) LightProbeSphere(LightProbe) LightProbeVolume(LightProbe) Lightgroup(bpy_struct) Lightgroups(bpy_struct) LimitDistanceConstraint(Constraint) LimitLocationConstraint(Constraint) LimitRotationConstraint(Constraint) LimitScaleConstraint(Constraint) LineStyleAlphaModifier(LineStyleModifier) LineStyleAlphaModifier_AlongStroke(LineStyleAlphaModifier) LineStyleAlphaModifier_CreaseAngle(LineStyleAlphaModifier) LineStyleAlphaModifier_Curvature_3D(LineStyleAlphaModifier) LineStyleAlphaModifier_DistanceFromCamera(LineStyleAlphaModifier) LineStyleAlphaModifier_DistanceFromObject(LineStyleAlphaModifier) LineStyleAlphaModifier_Material(LineStyleAlphaModifier) LineStyleAlphaModifier_Noise(LineStyleAlphaModifier) LineStyleAlphaModifier_Tangent(LineStyleAlphaModifier) LineStyleAlphaModifiers(bpy_struct) LineStyleColorModifier(LineStyleModifier) LineStyleColorModifier_AlongStroke(LineStyleColorModifier) LineStyleColorModifier_CreaseAngle(LineStyleColorModifier) LineStyleColorModifier_Curvature_3D(LineStyleColorModifier) LineStyleColorModifier_DistanceFromCamera(LineStyleColorModifier) LineStyleColorModifier_DistanceFromObject(LineStyleColorModifier) LineStyleColorModifier_Material(LineStyleColorModifier) LineStyleColorModifier_Noise(LineStyleColorModifier) LineStyleColorModifier_Tangent(LineStyleColorModifier) LineStyleColorModifiers(bpy_struct) LineStyleGeometryModifier(LineStyleModifier) LineStyleGeometryModifier_2DOffset(LineStyleGeometryModifier) LineStyleGeometryModifier_2DTransform(LineStyleGeometryModifier) LineStyleGeometryModifier_BackboneStretcher(LineStyleGeometryModifier) LineStyleGeometryModifier_BezierCurve(LineStyleGeometryModifier) LineStyleGeometryModifier_Blueprint(LineStyleGeometryModifier) LineStyleGeometryModifier_GuidingLines(LineStyleGeometryModifier) LineStyleGeometryModifier_PerlinNoise1D(LineStyleGeometryModifier) LineStyleGeometryModifier_PerlinNoise2D(LineStyleGeometryModifier) LineStyleGeometryModifier_Polygonalization(LineStyleGeometryModifier) LineStyleGeometryModifier_Sampling(LineStyleGeometryModifier) LineStyleGeometryModifier_Simplification(LineStyleGeometryModifier) LineStyleGeometryModifier_SinusDisplacement(LineStyleGeometryModifier) LineStyleGeometryModifier_SpatialNoise(LineStyleGeometryModifier) LineStyleGeometryModifier_TipRemover(LineStyleGeometryModifier) LineStyleGeometryModifiers(bpy_struct) LineStyleModifier(bpy_struct) LineStyleTextureSlot(TextureSlot) LineStyleTextureSlots(bpy_struct) LineStyleThicknessModifier(LineStyleModifier) LineStyleThicknessModifier_AlongStroke(LineStyleThicknessModifier) LineStyleThicknessModifier_Calligraphy(LineStyleThicknessModifier) LineStyleThicknessModifier_CreaseAngle(LineStyleThicknessModifier) LineStyleThicknessModifier_Curvature_3D(LineStyleThicknessModifier) LineStyleThicknessModifier_DistanceFromCamera(LineStyleThicknessModifier) LineStyleThicknessModifier_DistanceFromObject(LineStyleThicknessModifier) LineStyleThicknessModifier_Material(LineStyleThicknessModifier) LineStyleThicknessModifier_Noise(LineStyleThicknessModifier) LineStyleThicknessModifier_Tangent(LineStyleThicknessModifier) LineStyleThicknessModifiers(bpy_struct) Linesets(bpy_struct) LockedTrackConstraint(Constraint) LoopColors(bpy_struct) MASK_UL_layers(UIList) MATERIAL_UL_matslots(UIList) MESH_UL_attributes(UIList) MESH_UL_color_attributes(UIList) MESH_UL_color_attributes_selector(UIList) MESH_UL_uvmaps(UIList) MESH_UL_vgroups(UIList) Macro(bpy_struct) MagicTexture(Texture) MaintainVolumeConstraint(Constraint) MarbleTexture(Texture) Mask(ID) MaskLayer(bpy_struct) MaskLayers(bpy_struct) MaskModifier(Modifier) MaskParent(bpy_struct) MaskSpline(bpy_struct) MaskSplinePoint(bpy_struct) MaskSplinePointUW(bpy_struct) MaskSplinePoints(bpy_struct) MaskSplines(bpy_struct) MaskStrip(Strip) MaskStripModifier(StripModifier) Material(ID) MaterialGPencilStyle(bpy_struct) MaterialLineArt(bpy_struct) MaterialSlot(bpy_struct) Menu(bpy_struct) Mesh(ID) MeshCacheModifier(Modifier) MeshDeformModifier(Modifier) MeshEdge(bpy_struct) MeshEdges(bpy_struct) MeshLoop(bpy_struct) MeshLoopColor(bpy_struct) MeshLoopColorLayer(bpy_struct) MeshLoopTriangle(bpy_struct) MeshLoopTriangles(bpy_struct) MeshLoops(bpy_struct) MeshNormalValue(bpy_struct) MeshPolygon(bpy_struct) MeshPolygons(bpy_struct) MeshSequenceCacheModifier(Modifier) MeshSkinVertex(bpy_struct) MeshSkinVertexLayer(bpy_struct) MeshStatVis(bpy_struct) MeshToVolumeModifier(Modifier) MeshUVLoop(bpy_struct) MeshUVLoopLayer(bpy_struct) MeshVertex(bpy_struct) MeshVertices(bpy_struct) MetaBall(ID) MetaBallElements(bpy_struct) MetaElement(bpy_struct) MetaStrip(Strip) MirrorModifier(Modifier) Modifier(bpy_struct) ModifierViewerPathElem(ViewerPathElem) MotionPath(bpy_struct) MotionPathVert(bpy_struct) MovieClip(ID) MovieClipProxy(bpy_struct) MovieClipScopes(bpy_struct) MovieClipStrip(Strip) MovieClipUser(bpy_struct) MovieReconstructedCamera(bpy_struct) MovieStrip(Strip) MovieTracking(bpy_struct) MovieTrackingCamera(bpy_struct) MovieTrackingDopesheet(bpy_struct) MovieTrackingMarker(bpy_struct) MovieTrackingMarkers(bpy_struct) MovieTrackingObject(bpy_struct) MovieTrackingObjectPlaneTracks(bpy_struct) MovieTrackingObjectTracks(bpy_struct) MovieTrackingObjects(bpy_struct) MovieTrackingPlaneMarker(bpy_struct) MovieTrackingPlaneMarkers(bpy_struct) MovieTrackingPlaneTrack(bpy_struct) MovieTrackingPlaneTracks(bpy_struct) MovieTrackingReconstructedCameras(bpy_struct) MovieTrackingReconstruction(bpy_struct) MovieTrackingSettings(bpy_struct) MovieTrackingStabilization(bpy_struct) MovieTrackingTrack(bpy_struct) MovieTrackingTracks(bpy_struct) MulticamStrip(EffectStrip) MultiplyStrip(EffectStrip) MultiresModifier(Modifier) MusgraveTexture(Texture) NDOFMotionEventData(bpy_struct) NODE_AST_compositor(AssetShelf) NODE_FH_image_node(FileHandler) NlaStrip(bpy_struct) NlaStripFCurves(bpy_struct) NlaStrips(bpy_struct) NlaTrack(bpy_struct) NlaTracks(bpy_struct) Nod