merge-with

Merges this snip with the given snip, returning #f if the snips cannot be merged or a new merged snip otherwise. This method will only be invoked if both snips are from the same class and both have the 'can-append flag.

If the returned snip does not have the expected count, its count is forcibly modified. If the returned snip is already owned by a another administrator, a surrogate snip is created.

The snip's editor is usually internally locked for reading when this method is called (see also Locks).

• (send a-snip merge-with pred) -> snip% object or #f
      pred : snip% object

  Returns #f.