Bug 138562 Splite extendsexcpetion to seperate sub class
The suggestion is Parent invalid Cycle extends Different type extends Not top level extends
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
*/
	public final boolean canContain( Module module, int slotId,
			DesignElement element )
	{
		List errors = checkContainmentContext( module, slotId, element );
		if ( !errors.isEmpty( ) )
			return false;
		return true;
	}
	/**
	 * Determines if the slot can contain a given element.
	 * 
	 * @param module
	 *            the module
	 * @param slotId
	 *            the slot id
	 * @param element
	 *            the element to insert
	 * @return a list containing exceptions.
	 */
	public final List checkContainmentContext( Module module, int slotId,
			DesignElement element )
	{
		boolean retValue = canContainInRom( slotId, element.getDefn( ) );
		ContentException e = new ContentException( this, slotId, element,
				ContentException.DESIGN_EXCEPTION_INVALID_CONTEXT_CONTAINMENT );
		List errors = new ArrayList( );
		if ( !retValue )
		{
			errors.add( e );