code: function(destId, relationData, options) {
                  options = this.getDefaultOptions(options);
                  corbel.validate.value('destId', destId);
  
                  var args = corbel.utils.extend(options, {
                      url: this.buildUri(this.type, this.srcId, this.destType, destId),
                      data: relationData,
                      method: corbel.request.method.PUT,
                      contentType: options.dataType,
                      Accept: options.dataType
                  });
  
                  return this.request(args);
              }
docs: Adds a new relation between Resources
  @method
  @memberOf Resources.Relation
  @param  {String} destId          Relationed resource
  @param  {Object} relationData Additional data to be added to the relation (in json)
  @return {Promise}             ES6 promise that resolves to undefined (void) or rejects with a {@link CorbelError}
  @example uri = '555'