public static VoltXMLElement mergeTwoElementsUsingOperator(String opName,
                                                               String opElementId,
                                                               VoltXMLElement first,
                                                               VoltXMLElement second) {
        if (first == null || second == null) {
            return first == null ? second : first;
        }
        if (opName == null || opElementId == null) { return null; }

        VoltXMLElement retval = new VoltXMLElement("operation");
        retval.attributes.put( "id", opElementId );
        retval.attributes.put( "optype", opName );
        retval.children.add( first );
        retval.children.add( second );
        return retval;
    }
public static VoltXMLElement mergeTwoElementsUsingOperator ( String opName , String opElementId , VoltXMLElement first , VoltXMLElement second ) { if ( first == null || second == null ) { return first == null ? second : first ; } if ( opName == null || opElementId == null ) { return null ; } VoltXMLElement retval = new VoltXMLElement ( "operation" ) ; retval . attributes . put ( "id" , opElementId ) ; retval . attributes . put ( "optype" , opName ) ; retval . children . add ( first ) ; retval . children . add ( second ) ; return retval ; }
If one of the elements is null, return the other one diectly.