Bug 121498 When datasource/dataset deleted, the datasource/dataset property binding element haven't been deleted
When deleted the datasource/dataset, the datasource/dataset property binding element haven't been deleted. Expected result: This operation must be a transaction.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DesignElementHandle.java
}
	/**
	 * Returns the overridden value of the specified property given its internal
	 * name.
	 * 
	 * @param propName
	 *            the name of the property to get. Can be a system-defined or
	 *            user-defined property name.
	 * 
	 * @return the property binding, or null if the overridden value is not set
	 */
	public String getPropertyBinding( String propName )
	{
		PropertyBinding propBinding = module.findPropertyBinding(
				getElement( ), propName );
		if ( propBinding == null )
			return null;
		return propBinding.getValue( );
	}
	/**
	 * Sets the mask of the specified property.
	 * 
	 * @param propName
	 *            the property name to get. Can be a system-defined or
	 *            user-defined property name.
	 * 
	 * @param value
	 *            the overridden value
	 * 
	 * @throws SemanticException