call-as-primary-owner in editor-canvas%
Calls a thunk and returns the value. While the thunk is being called,
if the canvas has an editor, the editor's
get-admin method returns the administrator for this canvas. This method is
only useful when an editor is displayed in multiple canvases.
( -> return value of send an-editor-canvas call-as-primary-owner f)f
f : procedure of zero arguments
Returns (.f)