'Creates a new :class:`TransformNode`.
**shorthand_name** - a string representing the "name" of this
transform. The name carries no significance
other than to improve the readability of
``str(transform)`` when DEBUG=True.'

def __init__(self, shorthand_name=None):

    self._parents = {}
    self._invalid = 1
    self._shorthand_name = (shorthand_name or u'')
