--- instance_methods([inherited_too])
--- public_instance_methods([inherited_too])

    Υ⥸塼Ƥ public ᥽å̾ΰ֤ޤ

    inherited_too Ǥ(ǥեȤϵ)ѡ
    饹Υ᥽åɤõޤ

    (ruby 1.8 feature: ΥǥեȤϿѤͽǤ
    άȷٹ𤬽ФΤǡѹޤǤϰ뤳Ȥ˾
    ޤ)

    ruby 1.7 feature: instance_methods ϡprotected ᥽åɤ
    ޤߤޤ

    Object#methods [Object/methods],
    Object#public_methods [Object/public_methods],
    ⻲ȤƤ

        class Foo
          private;   def private_foo()   end
          protected; def protected_foo() end
          public;    def public_foo()    end
        end

        class Bar < Foo
        end

        p Bar.instance_methods(true)           - Object.instance_methods(true)
        p Bar.public_instance_methods(true)    - Object.public_instance_methods(true)
        p Bar.private_instance_methods(true)   - Object.private_instance_methods(true)
        p Bar.protected_instance_methods(true) - Object.protected_instance_methods(true)
        => ["public_foo"]   # version 1.7 ʹߡ["protected_foo", "public_foo"]
           ["public_foo"]
           ["private_foo"]
           ["protected_foo"]

