'initial limits for colorbar range. The returned min, max values
will be used to create colorbar solid(?) and etc.'

def _get_colorbar_limits(self):

    if (self.boundaries is not None):
        C = self.boundaries
        if (self.extend in [u'min', u'both']):
            C = C[1:]
        if (self.extend in [u'max', u'both']):
            C = C[:(-1)]
        return (min(C), max(C))
    else:
        return self.get_clim()
