'*child*: A class:`Transform` instance.  This child may later
be replaced with :meth:`set`.'

def __init__(self, child):

    if (not isinstance(child, Transform)):
        msg = u"'child'    must    be    an    instance    of    'matplotlib.transform.Transform'"
        raise ValueError(msg)
    self._init(child)
    self.set_children(child)
