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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 call(self, command, params=None, expect_body=True, stream=False):
 """ Sends the provided command to Serf for evaluation, with any parameters as the message body. """

        if self._socket is None:
            raise SerfConnectionError('handshake must be made first')

        header = msgpack.packb({"Seq": self._counter(), "Command": command})

        if params is not None:
            body = msgpack.packb(params)
            self._socket.sendall(header + body)
        else:
            self._socket.sendall(header)

        unpacker = msgpack.Unpacker(object_hook=self._decode_addr_key)

        def read_from_socket():
            try:
                buf = self._socket.recv(self._socket_recv_size)
                if len(buf) == 0:  # Connection was closed.
                    raise SerfConnectionError("Connection closed by peer")
                unpacker.feed(buf)
            except socket.timeout:
                raise SerfTimeout(
                    "timeout while waiting for an RPC response. (Have %s so"
                    "far)", response)

        if stream:
            def keep_reading_from_stream(init=[]):
                sub_response = SerfResult()
                while True:
                    if init is not None:
                        it = init
                        init = None
                    else:
                        if self._socket is None:
                            return
                        read_from_socket()
                        it = unpacker
                    for msg in it:
                        if sub_response.head is None:
                            sub_response.head = msg
                        elif sub_response.body is None:
                            sub_response.body = msg
                            yield sub_response
                            sub_response = SerfResult()
            mem = []
            messages_expected = 1
            while messages_expected > 0:
                read_from_socket()
                # Might have received enough to deserialise one or more
                # messages, try to fill out the response object.
                for message in unpacker:
                    mem.append(message)
                    messages_expected -= 1

            # Disable timeout while we are in streaming mode
            self._socket.settimeout(None)

            response = SerfResult()
            response.head = mem.pop()
            response.body = keep_reading_from_stream(mem)
        else:
            # The number of msgpack messages that are expected
            # in response to this command.
            messages_expected = 2 if expect_body else 1

            response = SerfResult()
            # Continue reading from the network until the expected number of
            # msgpack messages have been received.
            while messages_expected > 0:
                read_from_socket()
                # Might have received enough to deserialise one or more
                # messages, try to fill out the response object.
                for message in unpacker:
                    if response.head is None:
                        response.head = message
                    elif response.body is None:
                        response.body = message
                    else:
                        raise SerfProtocolError(
                            "protocol handler got more than 2 messages. "
                            "Unexpected message is: %s", message)

                    # Expecting one fewer message now.
                    messages_expected -= 1

        return response