code: function parseId(self, id) {
      const { options } = self.schema;
  
      if (is.string(id)) {
          if (options && options.keyType === 'name') {
              return id;
          } if (options.keyType === 'id') {
              return self.gstore.ds.int(id);
          }
          // auto convert string number to number
          return isFinite(id) ? self.gstore.ds.int(id) : id;
      }
  
      if (!is.number(id)) {
          throw new Error('id must be a string or a number');
      }
  
      return id;
  }
docs: Parse the id and according to the keyType config in the Schema ("name"|"id"|<undefined>)
  it will convert an '123'(string) id to 123 (int).
  @param {*} self -- the entity instance
  @param {*} id -- id passed in constructor