code: def rowstack(self, new, mode='nulls'):
          
          if isinstance(new,list):
              return tab_rowstack([self] + new, mode)
          else:
              return tab_rowstack([self, new], mode)
docs: Vertical stacking for tabarrays.
  
          Stack tabarray(s) in `new` below `self`.
  
          **See also**
  
                  :func:`tabular.tabarray.tab_rowstack`, 
                  :func:`tabular.spreadsheet.rowstack`