qiskit/quantum_info/operators/channel/choi.py
def _bipartite_shape(self):
        """Return the shape for bipartite matrix"""
        return (self._input_dim, self._output_dim, self._input_dim,
                self._output_dim)
def _bipartite_shape(self):
        """Return the shape for bipartite matrix"""
        return (self._input_dim, self._output_dim, self._input_dim,
                self._output_dim)
Return the shape for bipartite matrix