Bug 188578 Add "displayColumnName" on TabularLevel
Add Property "displayColumnName" on TabbularLevel and corresponding APIs on handle. Property Type: expression.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/writer/DocumentUtilTest.java
openDesign( "DocumentUtilTest_ElementProps.xml" ); 
		assertNotNull( designHandle );
		serializeDocument( );
		assertTrue( compareFile( "DocumentUtilTest_ElementProps_golden.xml" ) ); 
	}
	/**
	 * Tests a design file that is serialized by the document util.
	 * 
	 * @throws Exception
	 */
	public void testParserForSerializer( ) throws Exception
	{
		openDesign( "DocumentUtilTest_parser.xml" ); 
		assertNotNull( designHandle );
	}
	/**
	 * If two non-named element refers the same shared style, their names should
	 * not be style names.
	 * 
	 * @throws Exception
	 */
	public void testSerializeExternalSelectors( ) throws Exception
	{
		openDesign( DESIGN_WITH_EXTERNAL_SELECTORS );
		assertNotNull( designHandle );
		serializeDocument( );
		assertTrue( compareFile( "DocumentUtilTest_external_selectors_golden.xml" ) ); 
	}
}