Bug 153853 [Regression]The bound column names must be unique within the entire table.
Regression case Regression_136421(under org.eclipse.birt.report.tests.model) failed. Expected result: Model will avoid adding a duplicate bound column name within a table.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleHandle.java
{
		IModuleNameScope namescope = module
				.getModuleNameSpace( Module.DATA_SET_NAME_SPACE );
		List elementList = namescope
				.getElements( IModuleNameScope.NATIVE_LEVEL );
		return generateHandleList( elementList );
	}
	/**
	 * Returns the embedded images which are defined on the module itself. The
	 * embedded images defined in the included libraries will not be returned by
	 * this method.
	 * 
	 * @return the local embedded image list.
	 */
	public List getVisibleImages( )
	{
		List images = getNativeStructureList( Module.IMAGES_PROP );
		return images;
	}
	/**
	 * Returns all page handles that this modules and the included modules
	 * contain.
	 * 
	 * @return all page handles that this modules and the included modules
	 *         contain.
	 */
	public List getAllPages( )
	{
		List elementList = module.getNameSpace( Module.PAGE_NAME_SPACE )
				.getElements( );