missing_name?

# File activesupport/lib/active_support/core_ext/name_error.rb, line 10
  def missing_name?(name)
    if name.is_a? Symbol
      last_name = (missing_name || '').split('::').last
      last_name == name.to_s
    else
      missing_name == name.to_s
    end
  end