Bug 183918 get relative file path of linkage library
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/LibraryHandle.java
return ( (Library) module ).getNamespace( );
	}
	/**
	 * Returns a slot handle to work with the themes within the library. Note
	 * that the order of the data sets within the slot is unimportant.
	 * 
	 * @return A handle for working with the themes.
	 */
	public SlotHandle getThemes( )
	{
		return getSlot( THEMES_SLOT );
	}
	/**
	 * Returns a slot handle to work with the styles within the library.
	 * 
	 * @return A handle for working with the styles. Or <code>null</code> if
	 *         the library has no values for the theme property
	 * @deprecated uses the theme instead
	 */
	public SlotHandle getStyles( )
	{
		ThemeHandle theme = getTheme( );
		if ( theme == null )
			return null;
		return theme.getStyles( );
	}
	
	/**
	 * Import css file to theme.
	 *