def METHOD_NAME(self, pt, update_limits=True):
    """Add a single data point and update the plot.
    If the number of points exceeds the `length` of the data source,
    the oldest point will be ejected.
    If `update_limits` is `True` (the default) then the limits of the
    current data set are updated.
    """
    self._add(pt)
    if update_limits:
        self.update_limits()