/* set the function that will be executed when a friend request is received. */
void m_callback_friendrequest(void (*function)(uint8_t *, uint8_t *, uint16_t))
{
callback_friendrequest(function);
}
/* set the function that will be executed when a friend request is received. */
void m_callback_friendrequest(Messenger *m, void (*function)(uint8_t *, uint8_t *, uint16_t, void *), void *userdata)
{
callback_friendrequest(function, userdata);
}