def self.subs(model = nil, alt_object: nil, credentials: nil, model_version: "V2015_11_01")
        require 'azure_mgmt_subscriptions'

        if model and model.is_a?(Symbol)
          return Object.const_get("Azure").const_get("Subscriptions").const_get("Mgmt").const_get(model_version).const_get("Models").const_get(model)