code: def update_from_xlsx_blob(self, xlsx_blob):
          
          xlsx_part = self.xlsx_part
          if xlsx_part is None:
              self.xlsx_part = EmbeddedXlsxPart.new(xlsx_blob, self._package)
              return
          xlsx_part.blob = xlsx_blob
docs: Replace the Excel spreadsheet in the related |EmbeddedXlsxPart| with
          the Excel binary in *xlsx_blob*, adding a new |EmbeddedXlsxPart| if
          there isn't one.