def METHOD_NAME(self, bus):
    r"""
    Calculate the value of the bus function.
    Parameters
    ----------
    bus : tespy.connections.bus.Bus
        TESPy bus object.
    Returns
    -------
    residual : float
        Value of energy transfer :math:`\dot{E}`. This value is passed to
        :py:meth:`tespy.components.component.Component.calc_bus_value`
        for value manipulation according to the specified characteristic
        line of the bus.
        .. math::
            \dot{E} = \dot{m}_{in} \cdot \left(h_{out} - h_{in} \right)
    """
    return self.inl[0].m.val_SI * (
        self.outl[0].h.val_SI - self.inl[0].h.val_SI)