Return the gate width, using the settings (if available).

        :param string gate: The name of the gate whose height is desired.
        :return: Width of the gate.
        :rtype: float

def _gate_width(self, gate):
        """
        Return the gate width, using the settings (if available).

        :param string gate: The name of the gate whose height is desired.
        :return: Width of the gate.
        :rtype: float
        """
        try:
            gates = self.settings['gates']
            gate_width = gates[gate.__class__.__name__]['width']
        except KeyError:
            gate_width = .5
        return gate_width