class RSpec::Mocks::MethodReference

def self.method_visibility_for(object, method_name)
  vis = instance_method_visibility_for(class << object; self; end, method_name)
  # If the method is not defined on the class, `instance_method_visibility_for`
  # returns `nil`. However, it may be handled dynamically by `method_missing`,
  # so here we check `respond_to` (passing false to not check private methods).
  #
  # This only considers the public case, but I don't think it's possible to
  # write `method_missing` in such a way that it handles a dynamic message
  # with private or protected visibility. Ruby doesn't provide you with
  # the caller info.
  return vis unless vis.nil?
  proxy = RSpec::Mocks.space.proxy_for(object)
  respond_to = proxy.method_double_if_exists_for_message(:respond_to?)
  visible = respond_to && respond_to.original_method.call(method_name) ||
    object.respond_to?(method_name)
  return :public if visible
end