code: private boolean isPrivateHeaderTrusted(HeaderKeys key) {
          HttpServiceContextImpl hisc = getServiceContext();
          InetAddress remoteAddr = null;       
          String address = null;
          if (hisc != null && (remoteAddr = hisc.getRemoteAddr()) != null) {
              address = remoteAddr.getHostAddress();
          }
  
          boolean trusted = false;
          if (address != null) {
              trusted = HttpDispatcher.usePrivateHeaders(address, key.getName());
          }
  
          if (!trusted) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "isPrivateHeaderTrusted: " + key.getName() + " is not trusted for host " + address);
              }
              return false;
          }
          return true;
      }
docs: Check the to see if the current remote host is allowed to send a private header
  @see HttpDispatcher.usePrivateHeaders()
  
  @param key WAS private header
  @return true if the remote host is allowed to send key