    # File lib/fog/openstack/models/identity/ec2_credential.rb, line 26
            def save
              raise Fog::Errors::Error, 'Existing credentials cannot be altered' if
                access

              self.user_id   ||= user.id
              self.tenant_id ||= user.tenant_id

              requires :user_id, :tenant_id

              data = service.create_ec2_credential user_id, tenant_id

              merge_attributes(data.body['credential'])

              true
            end