Bug 119550 Default Value of Named Expression can't be saved in design file
New a report, set named expression in the report property editor add a named expression and set the default value add a report item, say table, to the layout set the named expression of the report item add a named expression and set hte default value save the report close the report and reopen, and there is no default named expression value displayed. open report design file with a text editor, there is no default value associate with the named expression
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/core/UserPropertyDefn.java
if ( displayName == null || hasChoices( ) == false )
			return null;
		IChoiceSet choiceSet = getChoices( );
		UserChoice choice = choiceSet.findUserChoiceByDisplayName( module,
				displayName );
		if ( choice != null )
			return choice.getName( );
		return null;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.metadata.PropertyDefn#getStructDefn()
	 */
	public IStructureDefn getStructDefn( )
	{
		return MetaDataDictionary.getInstance( ).getStructure( STRUCTURE_NAME );
	}
	/**
	 * User-defined methods are not supported.
	 * 
	 * @return <code>null</code>
	 */
	public MethodInfo getMethodInfo( )
	{
		assert false;
		return null;
	}
	/**
	 * Sets the property type.