Finds an editor-pane in an interface.
editor-pane
capi
interface-editor-pane interface => pane
interface
An instance of a subclass of interface.
pane
An editor-pane or nil .
nil
The generic function interface-editor-pane finds the first pane of interface that is an editor-pane, and returns it.
If there is no editor-pane, then interface-editor-pane returns nil .
editor-pane interface