Set the parent of the child reftrack node

        :param child: the child reftrack node
        :type child: str
        :param parent: the parent reftrack node
        :type parent: str
        :returns: None
        :rtype: None
        :raises: None

def set_parent(self, child, parent):
        """Set the parent of the child reftrack node

        :param child: the child reftrack node
        :type child: str
        :param parent: the parent reftrack node
        :type parent: str
        :returns: None
        :rtype: None
        :raises: None
        """
        parents = cmds.listConnections("%s.parent" % child, plugs=True, source=True)
        if parents:
            # there is only one parent at a time
            cmds.disconnectAttr("%s.parent" % child, "%s" % parents[0])
        if parent:
            cmds.connectAttr("%s.parent" % child, "%s.children" % parent, force=True, nextAvailable=True)