Bug 145520 Group name will not show up in group list if the group use default name and key expression has no value
Description: Group name will not show up in group list if key expression has no value. Steps to reproduce: 1. Insert a table into report, bind it to a data set 2. Switch to property editor -> groups 3. Click on add button to open new group dialog, then press ok button Expected result: A new group with default name will be added to group list Actual result: A new group is added to group list, but without group name. But when let group tab lost focus and get focus again, you can see the group name.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* Finds a shared style in this module itself.
	 * 
	 * @param name
	 *            Name of the style to find.
	 * @return The style, or null if the style is not found.
	 */
	public StyleElement findNativeStyle( String name )
	{
		return (StyleElement) nameSpaces[STYLE_NAME_SPACE].getElement( name );
	}
	/**
	 * Finds a shared style in this module and its included modules.
	 * 
	 * @param name
	 *            Name of the style to find.
	 * @return The style, or null if the style is not found.
	 */
	public StyleElement findStyle( String name )
	{
		ElementRefValue refValue = moduleNameSpaces[STYLE_NAME_SPACE].resolve(
				name, null );
		return (StyleElement) refValue.getElement( );
	}
	/**
	 * Finds a named report item in this module and the included modules. This
	 * is for body elements in the element's name space.
	 * 
	 * @param name
	 *            The name of the element to find.
	 * @return The element, or null if the element is not found.