Bug 122687 Libraries dont appear to allow background colors on tables to be used
If I create a table and set the background color to blue in my library and then drag the table from the library to the report the background color does not go with it.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
}
	/**
	 * Caches an element that derives from this element.
	 * <p>
	 * Part of: Inheritance system.
	 * 
	 * @param child
	 *            The new derived element.
	 */
	protected void addDerived( DesignElement child )
	{
		if ( derived == null )
			derived = new ArrayList( );
		assert child != null;
		assert child.getExtendsElement( ) == this;
		assert !derived.contains( child );
		assert child.getDefn( ) == getDefn( );
		derived.add( child );
	}
	/**
	 * Removes a cached element that derives from this element.
	 * <p>
	 * Part of: Inheritance system.
	 * 
	 * @param child
	 *            The old derived element.
	 */
	protected void dropDerived( DesignElement child )
	{
		assert derived != null;