code: def add(self, component: Union[Component, Sequence[Component]]) -> None:
          
          try:
              self[Span(*self._available_cell())] = component
          except NoUnusedCellsError:
              span = list(self._spans.keys())[-1]
              self._spans[span] += component
docs: Add a widget to the grid in the next available cell.
  
          Searches over columns then rows for available cells.
  
          Parameters
          ----------
          components : bowtie._Component
              A Bowtie widget instance.