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/command/ContentCommand.java
*            <code>true</code> to avoid the exception when the
	 *            <code>content</code> is a virtual element. Otherwise,
	 *            <code>false</code>.
	 * @throws SemanticException
	 *             if this content cannot be removed from container.
	 */
	public void remove( DesignElement content, int slotID,
			boolean unresolveReference, boolean flag ) throws SemanticException
	{
		doRemove( content, slotID, unresolveReference, flag );
	}
	/**
	 * @see #remove(DesignElement, int, boolean)
	 * @param content
	 *            the element to remove
	 * @param slotID
	 *            the slot from which to remove the content
	 * @param unresolveReference
	 *            status whether to un-resolve the references
	 * @param flag
	 *            Use the flag to indicate whether this method is do with the
	 *            element itself or do with its contents.
	 * @throws SemanticException
	 *             if this content cannot be removed from container.
	 */
	private void doRemove( DesignElement content, int slotID,
			boolean unresolveReference, boolean flag ) throws SemanticException
	{
		assert content != null;