Bug 176450 Support link to CSS Feature(Model Part)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/css/StyleSheetLoader.java
* @param properties
	 *            the properties to trim
	 * @return the trimmed property values
	 */
	LinkedHashMap trimProperties( LinkedHashMap properties )
	{
		assert properties != null;
		LinkedHashMap ret = new LinkedHashMap( );
		Iterator keys = properties.keySet( ).iterator( );
		while ( keys.hasNext( ) )
		{
			String key = (String) keys.next( );
			String value = (String) properties.get( key );
			if ( !StringUtil.isBlank( value ) )
				ret.put( key, value );
		}
		return ret;
	}
	/**
	 * Records a style sheet parser exception into the warning list.
	 * 
	 * @param e
	 *            the exception to record
	 */
	void semanticWarning( StyleSheetParserException e )
	{
		warnings.add( e );
		logger.log( Level.WARNING, e.getMessage( ) );
	}
}