code: function(_record) {
  
        if(packerCache) { // make sure this is a packer cache enabled context.
  
          var modelType = _record.$type,
              cache = packerCache[modelType.identity(true)];
  
          if(cache && _record.$pk) {
            for(var i = 0, l = cache.length; i < l; i++) {
              if(_record.$pk === modelType.inferKey(cache[i])) { // this could be sort of slow? nah
                _record.$decode(cache[i]);
                break;
              }
            }
          }
        }
  
        return _record;
      }
docs: IDEA: feedSingle: would require two step resolve many -> single 
  @memberof PackerCache#
  
  @description Searches for data matching the record's pk, if found data is then fed to the record using $decode.
  
  @param {RecordApi} _record restmod record to resolve, must be identified.
  @return {RecordApi} The record, so call can be nested.