Bug 213907 Provide a copy constructor for SubqueryDefinition.
Engine need a copy constructor to generate a SubqueryDefinition from an ISubqueryDefinition and change the name of the query.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedQuery.java
executor.setAppContext( this.appContext );
		
		
		
		logger.finer( "Start to prepare the execution." );
		executor.prepareExecution( outerResults, scope );
		logger.finer( "Finish preparing the execution." );
		QueryResults result = new QueryResults( new ServiceForQueryResults( this.session,
				executor.getQueryScope( ),
				executor.getNestedLevel( ) + 1,
				dataSourceQuery,
				queryService,
				executor,
				this.baseQueryDefn,
				this.exprManager ) );
		if( this.baseQueryDefn.cacheQueryResults() )
		{
			result.setID( QueryResultIDUtil.nextID( ) );
		}
		return result;
	}
	
	/**
	 * @param subQueryName
	 * @return
	 */
	ISubqueryDefinition getSubQueryDefn( String subQueryName )
	{