--- remove_method(name)
--- remove_method(name[, name2, ...])   ruby 1.8 feature

    name ǻꤷ󥹥󥹥᥽åɤ⥸塼뤫
    ޤ⤷ꤷ᥽åɤƤʤȤˤ㳰
    NameError ȯޤ

        class Foo
          def foo() end
          remove_method(:foo)
        end

    ruby 1.8 feature: ʣΥ᥽åɤ٤˻ꤹ뤳ȤǤޤ

    self ֤ޤ

    undef_method ⻲ȤƤ

