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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 _prepare_socket_file(self, socket_path, default_prefix):
 """Prepare the socket file for raylet and plasma. This method helps to prepare a socket file. 1. Make the directory if the directory does not exist. 2. If the socket file exists, raise exception. Args: socket_path (string):
 the socket file to prepare. """

        if socket_path is not None:
            if os.path.exists(socket_path):
                raise Exception("Socket file {} exists!".format(socket_path))
            socket_dir = os.path.dirname(socket_path)
            try_to_create_directory(socket_dir)
            return socket_path
        return self._make_inc_temp(
            prefix=default_prefix, directory_name=self._sockets_dir)