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
public CssStyleSheetHandle openCssStyleSheet( InputStream is )
			throws StyleSheetException
	{
		StyleSheetLoader loader = new StyleSheetLoader( );
		return loader.load( module, is ).handle( module );
	}
	/**
	 * Imports the selected styles in a <code>CssStyleSheetHandle</code> to
	 * the module. Each in the list is instance of
	 * <code>SharedStyleHandle</code> .If any style selected has a duplicate
	 * name with that of one style already existing in the report design, this
	 * method will rename it and then add it to the design.
	 * 
	 * @param stylesheet
	 *            the style sheet handle that contains all the selected styles
	 * @param selectedStyles
	 *            the selected style list
	 * 
	 * 
	 */
	abstract public void importCssStyles( CssStyleSheetHandle stylesheet,
			List selectedStyles );
	/**
	 * Sets the theme to a report.
	 * 
	 * @param themeName
	 *            the name of the theme
	 * @throws SemanticException
	 */
	public void setThemeName( String themeName ) throws SemanticException