code: def clone_master_placeholders(self, notes_master):
          
          def iter_cloneable_placeholders(notes_master):
              """
              Generate a reference to each placeholder in *notes_master* that
              should be cloned to a notes slide when the a new notes slide is
              created.
              """
              cloneable = (
                  PP_PLACEHOLDER.SLIDE_IMAGE,
                  PP_PLACEHOLDER.BODY,
                  PP_PLACEHOLDER.SLIDE_NUMBER,
              )
              for placeholder in notes_master.placeholders:
                  if placeholder.element.ph_type in cloneable:
                      yield placeholder
  
          shapes = self.shapes
          for placeholder in iter_cloneable_placeholders(notes_master):
              shapes.clone_placeholder(placeholder)
docs: Selectively add placeholder shape elements from *notes_master* to the
          shapes collection of this notes slide. Z-order of placeholders is
          preserved. Certain placeholders (header, date, footer) are not
          cloned.