def getCallBack(self, ps, post, action):
node = self.getNode(post)<EOL>if node is None:<EOL><INDENT>raise NoSuchFunction<EOL><DEDENT>if node.authorize(None, post, action):<EOL><INDENT>return node.getOperation(ps, action)<EOL><DEDENT>else:<EOL><INDENT>raise NotAuthorized("<STR_LIT>" % action)<EOL><DEDENT>
post -- POST HTTP value
           action -- SOAP Action value