Bug 118750 Insert group for table from library, system throws exception.
Insert group for table from library, system throws exception. Steps: 1.Insert a tabel from library 2.Insert group Actual Results: 1.System throws exception A Birt exception occurred. Plug-in Provider:Eclipse.org Plug-in Name:BIRT Model Plug-in ID:org.eclipse.birt.report.model Version:1.0.1 Error Code:Error.ContentException.STRUCTURE_CHANGE_FORBIDDEN Error Message:Element "report.Body[1]" is child element or a virtual element( inside the child ), can not change its structure. Expected Results: 1.Can be inserted group
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/core/model/schematic/TableHandleAdapter.java
*            position, negative insert before the position
	 * @param baseColumnNumber
	 *            The column position in the table.
	 * @throws SemanticException
	 */
	public void insertColumns( int columnCount, int baseColumnNumber )
			throws SemanticException
	{
		transStar( TRANS_LABEL_INSERT_COLUMN );
		int absoluteCount = Math.abs( columnCount );
		int sign = columnCount / absoluteCount;
		for ( int i = 0; i < absoluteCount; i++ )
		{
			insertColumn( sign, baseColumnNumber );
		}
		transEnd( );
	}
	/**
	 * @param model
	 *            The object to be removed.
	 * @throws SemanticException
	 */
	public void removeChild( Object model ) throws SemanticException
	{
		assert ( model instanceof DesignElementHandle );
		DesignElementHandle ele = (DesignElementHandle) model;
		ele.drop( );
	}
	/**
	 * Delete specific columns from the current table.