code: function(set) {
          var dtype, valids, typeClass, self = this;
          //
          if (utils.isString(set)) {
              // resolve data type
              typeClass = this.dataTypes.get(set);
              if (typeClass) { dtype = new typeClass(); }
          }
          else if (set) {
              utils.each(set, function(key, val) {
                  if (!utils.hasOwn(set, key)) {
                      return;
                  }
                  if (key.toLowerCase() === 'type') {
                      // resolve data type
                      typeClass = self.dataTypes.get(val);
                      if (typeClass) { dtype = new typeClass(); }
                  } else {
                      // resolve validators
                      typeClass = self.validators.get(key);
                      if (typeClass) {
                          if (!valids) { valids = []; }
                          valids.push(new typeClass(set[key]));
                      }
                  }
              });
          }
          return new modellingMetas(dtype, valids);
      }
docs: /*
  reslove setting to sepcified data type class and valiadator classes
  set: { type: 'string', required: true, ... }  /  set: 'string'