code: function(connection, collection, object, cb) {
        utils.removeCircularReferences(object);
        if (cb) {
          cb(object);
        }
        return object;
      }
docs: Remove Circular References
  
  Replaces circular references with `id` when one is available, otherwise it replaces the object
  with string '[Circular]'
  
  @param {Object} connection
  @param {Object} collection
  @param {Object} object
  @param {Object} cb