code: public void setAlpnProtocol(String protocol) {
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "setAlpnProtocol: " + protocol + " " + this);
          }
          this.alpnProtocol = protocol;
          this.sslConnectionContext.setAlpnProtocol(protocol);
      }
docs: Set the ALPN protocol negotiated for this link
  
  @param String protocol