self <= other -> bool
self が other のサブセットか同じである場合に真を返します。
例 h1 = {a:1, b:2} h2 = {a:1, b:2, c:3} h1 <= h2 # => true h2 <= h1 # => false h1 <= h1 # => true
h1 = {a:1, b:2} h2 = {a:1, b:2, c:3} h1 <= h2 # => true h2 <= h1 # => false h1 <= h1 # => true
[SEE_ALSO] Hash#<, Hash#>=, Hash#>