class RSpec::Support::ObjectFormatter::UninspectableObjectInspector

def native_object_id

http://stackoverflow.com/a/2818916
def native_object_id
  OBJECT_ID_FORMAT % (object.__id__ << 1)
rescue NoMethodError
  # In Ruby 1.9.2, BasicObject responds to none of #__id__, #object_id, #id...
  '-'
end