'make sure included schema has same tns.'

def __applytns(self, root):

    TNS = 'targetNamespace'
    tns = root.get(TNS)
    if (tns is None):
        tns = self.schema.tns[1]
        root.set(TNS, tns)
    elif (self.schema.tns[1] != tns):
        raise Exception, ('%s    mismatch' % TNS)
