code: static Class<? extends DatagramChannel> getDatagramChannelClass(final EventLoopGroup eventLoopGroup) {
          Objects.requireNonNull(eventLoopGroup);
  
          final String datagramChannelClassName = DATAGRAM_CHANNEL_CLASSES.get(eventLoopGroup.getClass().getName());
  
          if (datagramChannelClassName == null) {
              throw new IllegalArgumentException("No datagram channel class found for event loop group type: " + eventLoopGroup.getClass().getName());
          }
  
          try {
              return Class.forName(datagramChannelClassName).asSubclass(DatagramChannel.class);
          } catch (final ClassNotFoundException e) {
              throw new IllegalArgumentException(e);
          }
      }
docs: Returns a datagram channel class suitable for specified event loop group.
  
  @param eventLoopGroup the event loop group for which to identify an appropriate datagram channel class; must not
  be {@code null}
  
  @return a datagram channel class suitable for use with the given event loop group
  
  @throws IllegalArgumentException in case of null or unrecognized event loop group