def delete(params={})
      key = params.delete(:key)
      Zcloudjp::Client.delete("/machines/#{machine.id}/metadata/#{key}", machine.request_options)
    end
def delete(params={})
      key = params.delete(:key)
      Zcloudjp::Client.delete("/machines/#{machine.id}/metadata/#{key}", machine.request_options)
    end
DELETE /machines/:id/metadata/:key.:format