public Boolean proxyCallRestricted() {
      if (allowedHostPorts == null) {
        initializeAllowedHostPorts();
      }
      return isProxyCallRestricted;
    }
Is there a restriction of which host and port the call can be made to
@return
ambari-server/src/main/java/org/apache/ambari/server/view/ViewURLStreamProvider.java