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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 make_heartbeat(port, path, peer_uid, node_uid, app_id):
 """ Prepares the heart beat UDP packet Format : Little endian * Kind of beat (1 byte) * Herald HTTP server port (2 bytes) * Herald HTTP servlet path length (2 bytes) * Herald HTTP servlet path (variable, UTF-8) * Peer UID length (2 bytes) * Peer UID (variable, UTF-8) * Node UID length (2 bytes) * Node UID (variable, UTF-8) * Application ID length (2 bytes) * Application ID (variable, UTF-8) :param port: The port to access the Herald HTTP server :param path: The path to the Herald HTTP servlet :param peer_uid: The UID of the peer :param node_uid: The UID of the node :param app_id: Application ID :return: The heart beat packet content (byte array) """

    # Type and port...
    packet = struct.pack("<BBH", PACKET_FORMAT_VERSION, PACKET_TYPE_HEARTBEAT, port)
    for string in (path, peer_uid, node_uid, app_id):
        # Strings...
        string_bytes = to_bytes(string)
        packet += struct.pack("<H", len(string_bytes))
        packet += string_bytes

    return packet