qualified_const_defined?

# File activesupport/lib/active_support/core_ext/module/qualified_const.rb, line 26
  def qualified_const_defined?(path, search_parents=true)
    QualifiedConstUtils.raise_if_absolute(path)

    QualifiedConstUtils.names(path).inject(self) do |mod, name|
      return unless mod.const_defined?(name, search_parents)
      mod.const_get(name)
    end
    return true
  end