enum net_async_status
mysql_free_result_nonblocking(MYSQL_RES *result)
            mysql_free_result_nonblocking()
            is an asynchronous function. It is the counterpart of the
            mysql_free_result()
            synchronous function, for use by applications that require
            asynchronous communication with the server. For general
            information about writing asynchronous C API applications,
            see Chapter 7, C API Asynchronous Interface.
          
          mysql_free_result_nonblocking()
          is used similarly to
          mysql_free_result(). For
          details about the latter, see
          Section 5.4.26, “mysql_free_result()”. The two functions differ
          as follows:
        
- mysql_free_result()does not return a value.
- mysql_free_result_nonblocking()returns an- enum net_async_statusstatus indicator.
          mysql_free_result_nonblocking()
          was added in MySQL 8.0.16.
        
          Returns an enum net_async_status value. See
          the description in
          Section 7.2, “C API Asynchronous Interface Data Structures”. A
          NET_ASYNC_ERROR return status indicates an
          error.