Using Object#to_enum from response-body to Enumerator, not Object#each.
Using Object#to_enum from response-body to Enumerator, not Object#each.

Using Object#to_enum from response-body to Enumerator Object,
not Object#using beacause of Rack::Lint#each doesn't return Enumerator.
And add check to response-body respond to `each` method.

kubo39/bossan,kubo39/bossan,kubo39/bossan