@Override
      public void appendTo(StringBuffer buffer) {
        buffer.append("eqClusterEnv(");
        buffer.append(wrapper);
        buffer.append(")");
      }
Tests merging configurations between existing and new stack values on
upgrade.

@throws Exception
ambari-server/src/test/java/org/apache/ambari/server/stack/upgrade/orchestrate/UpgradeHelperTest.java