def METHOD_NAME(self, depth, receiver_depth=None):
    """
    Corrects the TauModel for the given source depth (if not already
    corrected).
    """
    if receiver_depth is None:
        receiver_depth = self.receiver_depth
    if self.depth_corrected_model is None or \
            self.depth_corrected_model.source_depth != depth:
        self.depth_corrected_model = self.model.METHOD_NAME(depth)
        self.arrivals = []
    if receiver_depth != depth:
        # If already split on receiver depth this does nothing.
        self.depth_corrected_model = \
            self.depth_corrected_model.split_branch(receiver_depth)
        self.arrivals = []
    self.source_depth = depth
    self.receiver_depth = receiver_depth