'*which* : "major" or "minor"
*axis* : "both", "x" or "y"'

def __init__(self, *kl, **kwargs):

    self._which = kwargs.pop(u'which', u'major')
    self._axis = kwargs.pop(u'axis', u'both')
    super(GridlinesCollection, self).__init__(*kl, **kwargs)
    self.set_grid_helper(None)
