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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def expectWithHeader(self, expectedHeaderLen, callbackBody):
 """ 2nd level of waiting event read expectedHeaderLen that contain body size @param expectedHeaderLen: contains the number of bytes, which body length needs to be encoded @param callbackBody: next state use when expected date from expectedHeaderLen are received """

        self._callbackBody = callbackBody
        self.expect(expectedHeaderLen, self.expectedBody)