code: function(identity) {
                  corbel.validate.isValue(identity, 'Missing identity');
                  corbel.validate.value('id', this.id);
                  console.log('iamInterface.user.addIdentity', identity);
                  return this.request({
                      url: this._buildUriWithDomain(this.uri, this.id) + '/identity',
                      method: corbel.request.method.POST,
                      data: identity
                  });
              }
docs: Adds an identity (link to an oauth server or social network) to the user
  @method
  @memberOf corbel.Iam.UserBuilder
  @param {Object} identity     The data of the identity
  @param {string} oauthId      The oauth ID of the user
  @param {string} oauthService The oauth service to connect (facebook, twitter, google, corbel)
  @return {Promise}  Q promise that resolves to undefined (void) or rejects with a {@link corbelError}