code: public SslContext createHttp2TLSContextForServer(SSLConfig sslConfig) throws SSLException {
  
          // If listener configuration does not include cipher suites , default ciphers required by the HTTP/2
          // specification will be added.
          createSSLContextFromKeystores(true);
          List<String> ciphers = sslConfig.getCipherSuites() != null && sslConfig.getCipherSuites().length > 0 ?
                  Arrays.asList(sslConfig.getCipherSuites()) :
                  Http2SecurityUtil.CIPHERS;
          SslProvider provider = SslProvider.OPENSSL;
          if (sslConfig.getKeyStore() != null) {
              sslContextBuilder = serverContextBuilderWithKs(provider);
          } else {
              sslContextBuilder = serverContextBuilderWithCerts(provider);
          }
          setCiphers(sslContextBuilder, ciphers);
          setSslProtocol(sslContextBuilder);
          setAlpnConfigs(sslContextBuilder);
          setOcspStapling(sslContextBuilder, sslConfig.isOcspStaplingEnabled());
  
          SslContext sslCtx = sslContextBuilder.build();
          int sessionTimeout = sslConfig.getSessionTimeOut();
          if (sessionTimeout > 0) {
              sslCtx.sessionContext().setSessionTimeout(sessionTimeout);
          }
  
          return sslCtx;
      }
docs: This method will provide netty ssl context which supports HTTP2 over TLS using
  Application Layer Protocol Negotiation (ALPN)
  
  @param sslConfig ssl configurations
  @return instance of {@link SslContext}
  @throws SSLException if any error occurred during building SSL context.