code: function (identifier) {
              var self = this;
  
              return self.needByIdentifier(identifier)
                  .then(function (record) {
                      return self.destroy(
                         record.id
                      ).then(function (records) {
                          return records[0];
                      });
                  });
          }
docs: Look up and remove objects by identifier - either the "id" or in the identifiers array.
  Returns a waterline (bluebird) promise with the record deleted
  Rejects the promise if the document was not found.
  @param {string} identifier
  @returns {Deferred}