Sends a command to all server nodes.

        Sending command to a server node will cause that server node to invoke
        ``KVStoreServer.controller`` to execute the command.

        This function returns after the command has been executed on all server
        nodes.

        Parameters
        ----------
        head : int
            the head of the command.
        body : str
            the body of the command.

def _send_command_to_servers(self, head, body):
        """Sends a command to all server nodes.

        Sending command to a server node will cause that server node to invoke
        ``KVStoreServer.controller`` to execute the command.

        This function returns after the command has been executed on all server
        nodes.

        Parameters
        ----------
        head : int
            the head of the command.
        body : str
            the body of the command.
        """
        check_call(_LIB.MXKVStoreSendCommmandToServers(
            self.handle, mx_uint(head), c_str(body)))