focusManager.setFocus doesn't works with ADG's id,throwing compile time Error

On line : focusManager.setFocus(dgServices);
dgServices is id of ADG
Error: Implicit coercion of a value of type mx.controls.AdvancedDataGrid to an unrelated type mx.managers.IFocusManagerComponent.

Example: https://paste.apache.org/7harh

Start by reproducing the compile-time error from the paste example at focusManager.setFocus(dgServices), where dgServices is the AdvancedDataGrid id. Trace the setFocus entry point and the AdvancedDataGrid type involved; done means the example compiles and focus can be set on the grid without the reported coercion error.

Written by the indexing model from the issue text.