Bug 176450 Support link to CSS Feature(Model Part)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/ReferenceableElement.java
BackRef ref = (BackRef) clients.get( i );
			if ( ref.element == client
					&& ( propName == null || ref.propName.equals( propName ) ) )
			{
				clients.remove( i );
				return;
			}
		}
		assert false;
	}
	/**
	 * Returns the list of clients for this element.
	 * 
	 * @return The list of clients.
	 */
	public List getClientList( )
	{
		return new ArrayList( clients );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.core.IReferencable#hasReferences()
	 */
	public boolean hasReferences( )
	{
		return !clients.isEmpty( );
	}
	/**
	 * Sends the event to all clients in addition to the routing for a design