--- ENV.indexes(key_1, ... , key_n)
--- ENV.indices(key_1, ... , key_n)

    ǻꤵ줿̾δĶѿ֤ͤޤ

    ruby 1.8 feature:
    Υ᥽åɤ version 1.8 Ǥϡobsolete Ǥ
    Ѥȷٹåɽޤ
     ENV.values_at Ѥޤ

