code: protected void getAndRemoveIbmAlpnChoice(SSLEngine engine, SSLConnectionLink link) {
          if (this.isIbmAlpnActive()) {
              try {
                  // invoke ALPNJSSEExt.get(engine)
                  String[] alpnResult = (String[]) ibmAlpnGet.invoke(null, engine);
  
                  // invoke ALPNJSSEExt.delete(engine)
                  ibmAlpnDelete.invoke(null, engine);
  
                  if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                      StringBuilder sb = new StringBuilder();
                      sb.append("getAndRemoveIbmAlpnChoice");
                      if (alpnResult != null && alpnResult.length > 0) {
                          sb.append(" results:");
                          for (String s : alpnResult) {
                              sb.append(" " + s);
                          }
                          sb.append(" " + engine);
                      } else {
                          sb.append(": ALPN not used for " + engine);
                      }
                      Tr.debug(tc, sb.toString());
                  }
  
                  if (alpnResult != null && alpnResult.length == 1 && h2.equals(alpnResult[0])) {
                      if (link.getAlpnProtocol() == null) {
                          link.setAlpnProtocol(h2);
                      }
                  }
              } catch (InvocationTargetException ie) {
                  if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                      Tr.debug(tc, "getAndRemoveIbmAlpnChoice exception: " + ie.getTargetException());
                  }
              } catch (Exception e) {
  
                  if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                      Tr.debug(tc, "getAndRemoveIbmAlpnChoice exception: " + e);
                  }
              }
          }
      }
docs: Ask the JSSE ALPN provider for the protocol selected for the given SSLEngine, then delete the engine from
  the ALPN provider's map. If the selected protocol was "h2", set that as the protocol to use on the given link.
  
  @param SSLEngine
  @param SSLConnectionLink