Check whether the object_id id is in the current buffer of objects
to be pretty printed. Used to break cycles in chains of objects to be
pretty printed.
# File lib/pp.rb, line 129
def check_inspect_key(id)
Thread.current[:__recursive_key__] &&
Thread.current[:__recursive_key__][:inspect] &&
Thread.current[:__recursive_key__][:inspect].include?(id)
end