code: def new(cls, partname, package, slide_layout_part):
          
          sld = CT_Slide.new()
          slide_part = cls(partname, CT.PML_SLIDE, sld, package)
          slide_part.relate_to(slide_layout_part, RT.SLIDE_LAYOUT)
          return slide_part
docs: Return a newly-created blank slide part having *partname* and related
          to *slide_layout_part*.