code: def ph_basename(self, ph_type):
          
          return {
              PP_PLACEHOLDER.BODY:         'Notes Placeholder',
              PP_PLACEHOLDER.DATE:         'Date Placeholder',
              PP_PLACEHOLDER.FOOTER:       'Footer Placeholder',
              PP_PLACEHOLDER.HEADER:       'Header Placeholder',
              PP_PLACEHOLDER.SLIDE_IMAGE:  'Slide Image Placeholder',
              PP_PLACEHOLDER.SLIDE_NUMBER: 'Slide Number Placeholder',
          }[ph_type]
docs: Return the base name for a placeholder of *ph_type* in this shape
          collection. A notes slide uses a different name for the body
          placeholder and has some unique placeholder types, so this
          method overrides the default in the base class.