Bug 120317 Set "dimension" property to 3D in "properties" view, error appears in layout editor.
Description: Set "dimension" property to 3D in "properties" view, error appears in layout editor. Steps to reproduce: 1. Add a 2D chart in property editor. 2. Set its dimension property to "three-dimension" in properties view. 3. Error appears in chart.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ExtensionModelPropertyDefn.java
return null;
		if ( choices.size( ) == 0 )
			return null;
		Choice[] choiceArray = new Choice[choices.size( )];
		Iterator iter = choices.iterator( );
		int i = 0;
		while ( iter.hasNext( ) )
		{
			IChoiceDefinition choice = (IChoiceDefinition) iter.next( );
			ExtensionChoice extChoice = new ExtensionChoice( choice, messages );
			choiceArray[i] = extChoice;
			i++;
		}
		assert i == choices.size( );
		ChoiceSet set = new ChoiceSet( );
		set.setChoices( choiceArray );
		details = set;
		return set;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.metadata.PropertyDefn#getDefault()
	 */
	public Object getDefault( )
	{
		return extProperty.getDefaultValue( );
	}
	/*
	 * Returns the localized display name, if non-empty string can be found with