def multiply(self, other):
if not isinstance(other, Number):<EOL><INDENT>raise QiskitError("<STR_LIT>")<EOL><DEDENT>return PTM(other * self._data, self._input_dims, self._output_dims)<EOL>
Return the QuantumChannel self + other.

        Args:
            other (complex): a complex number.

        Returns:
            PTM: the scalar multiplication other * self as a PTM object.

        Raises:
            QiskitError: if other is not a valid scalar.