'Append a cell into the stack.
Parameters
cell : BaseRNNCell
The cell to be appended. During unroll, previous cell\'s output (or raw inputs if
no previous cell) is used as the input to this cell.'

def add(self, cell):

    self._cells.append(cell)
    if self._override_cell_params:
        assert cell._own_params, 'Either    specify    params    for    SequentialRNNCell    or    child    cells,    not    both.'
        cell.params._params.update(self.params._params)
    self.params._params.update(cell.params._params)
