Bug 136270 Group's data binding column can only be used by the group itself
If you add some data binding columns to a group, these columns can only be used by this group itself. It should has a way to make the child can use the parent group's data binding column.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
}
				return null;
			}
		}
		return null;
	}
	/**
	 * Get a DesignElementHandle's method's all arguments.
	 * 
	 * @param handle
	 * @param methodName
	 * @return Arguments map, key is argument name, value is argument type.
	 */
	public static Map getDesignElementMethodArguments(
			DesignElementHandle handle, String methodName )
	{
		List methods = handle.getDefn( ).getMethods( );