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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 send(self, obj):
 """Prepend a 4-byte length to the string"""

        assert isinstance(obj, ProtocolBase)
        string = pickle.dumps(obj)
        length = len(string)
        self.sock.sendall(struct.pack("<I", length) + string)