Panes set an implicit state within the overall application when activated. Many user interface elements
respond to changes in application state; for example, different tabs appear depending on the type of Pane activated. When
a Pane is activated, its DAML ID is by default added to application level State; the Impersonate
method allows the Pane to override this behavior and instead specify a custom state.
For example, when a Map is activated inside a Layout, the Layout impersonates a Map Pane so that all of the mapping
functionality will become available to the activated Map.