code: function _filterByObjectSchema(data, schema) {
      return Object
          .keys(data)
          .filter(function (key) {
              return schema.hasOwnProperty(key);
          })
          .reduce(function (memo, key) {
              var value = data[key];
              var schemaPart = schema[key];
              if (typeof schemaPart === 'object') {
                  memo[key] = _filter(value, schemaPart);
              } else {
                  memo[key] = value;
              }
              return memo;
          }, {});
  }
docs: Filters an object from an object schema
  @param data Object to filter
  @param schema Fields to keep
  @returns {*}
  @private