code: function dataSource(type) {
    if (arguments.length === 1 && (utils.isObject(type) || typeof type === 'string')) {
      return type
    }
    else if (!ds.hasOwnProperty(type)) {
      throw new FieldError('Unknown data source type: ' + type)
    }
  
    var args = utils.args(arguments, 1)
      , dataSource = {
        type: type
      }
  
    ds[type].apply(dataSource, args)
  
    return dataSource
  }
docs: Set data source
  
  @param {string} type Data source as string or as object. Or data source type
  @param {...*} args Arguments specific to each data source type