code: def split(self):
          
          if not self.is_merge_origin:
              raise ValueError(
                  'not a merge-origin cell; only a merge-origin cell can be sp'
                  'lit'
              )
  
          tc_range = TcRange.from_merge_origin(self._tc)
  
          for tc in tc_range.iter_tcs():
              tc.rowSpan = tc.gridSpan = 1
              tc.hMerge = tc.vMerge = False
docs: Remove merge from this (merge-origin) cell.
  
          The merged cell represented by this object will be "unmerged",
          yielding a separate unmerged cell for each grid cell previously
          spanned by this merge.
  
          Raises |ValueError| when this cell is not a merge-origin cell. Test
          with `.is_merge_origin` before calling.