Returns the X cursor belonging to a `GdkCursor`, potentially creating the cursor.
Be aware that the returned cursor may not be unique to cursor
. It may for example be shared with its fallback cursor. On old
X servers that don't support the XCursor extension, all cursors may even fall back to a few default cursors.
this |
a `GdkDisplay` |
cursor |
a `GdkCursor` |
an Xlib Cursor. |