def attribute(self, name):
        """Expression for an input attribute.

        An input attribute is an attribute on the input
        port of the operator invocation.

        Args:
            name(str): Name of the attribute.
           
        Returns:
            Expression: Expression representing the input attribute.
        """
        return super(Map, self).attribute(self._inputs[0], name)
Expression for an input attribute.

        An input attribute is an attribute on the input
        port of the operator invocation.

        Args:
            name(str): Name of the attribute.
           
        Returns:
            Expression: Expression representing the input attribute.