def demo_Sketches_addToBaseOrFeature(rootComp: adsk.fusion.Design.rootComponent):
# Create a base feature
baseFeats = rootComp.features.baseFeatures
targetBaseOrFormFeature = baseFeats.add()
# To make changes to a base feature, it must be in an edit state.
targetBaseOrFormFeature.startEdit()
# Create a sketch in the base feature on the XY base plane.
sketches = rootComp.sketches
includeFaceEdges = True
sketch = sketches.addToBaseOrFormFeature(rootComp.xYConstructionPlane, targetBaseOrFormFeature, includeFaceEdges)
# Exit from the base Feature.
targetBaseOrFormFeature.finishEdit()