typedef struct bt_port_input bt_port_input;
typedef struct bt_port_output bt_port_output;
typedef struct bt_port_output_message_iterator bt_port_output_message_iterator;
typedef struct bt_port_input bt_port_input;
typedef struct bt_port_output bt_port_output;
typedef struct bt_port_output_message_iterator bt_port_output_message_iterator;