Bug 162167 Add API IResultIterator.isEmpty to Data Engine.
Current DTE api do not have a method that can be directly used to tell the client whether an IResultIterator is empty or not.We need to add this api for the convenience sake.
engine/org.eclipse.birt.report.engine.tests/test/org/eclipse/birt/report/engine/api/script/RowDataTest.java
return null;
		}
		public void skipToEnd( int groupLevel ) throws BirtException
		{
		}
		public int getStartingGroupLevel( ) throws BirtException
		{
			return 0;
		}
		public int getEndingGroupLevel( ) throws BirtException
		{
			return 0;
		}
		public IResultIterator getSecondaryIterator( String subQueryName,
				Scriptable scope ) throws BirtException
		{
			return null;
		}
		public void close( ) throws BirtException
		{
		}
		public boolean findGroup( Object[] groupKeyValues )
				throws BirtException
		{
			return false;
		}
		public int getRowId( ) throws BirtException
		{
			return 0;
		}