Toggle auto hide for a docked window pane

Click the pushpin icon () located in the right side of the window pane title bar.
The docked window pane collapses into a tab attached the application window edge it is docked into. Hovering the mouse pointer over this tab expands the window pane for use. Once the mouse is clicked outside the window pane, it will "auto hide" once again.

Note: Clicking the window pane tab will show the window pane without pause.
Clicking the horizontal pushpin icon again will make the window pane "sticky" (toggle off auto hide).