text: var utils = require('../utils')
    , nodes = require('../nodes');
  
  /**
   * Assign `type` to the given `unit` or return `unit`'s type.
   *
   * @param {Unit} unit
   * @param {String|Ident} type
   * @return {Unit}
   * @api public
   */
  
  function unit(unit, type){
    utils.assertType(unit, 'unit', 'unit');
  
    // Assign
    if (type) {
      utils.assertString(type, 'type');
      return new nodes.Unit(unit.val, type.string);
    } else {
      return unit.type || '';
    }
  }
  unit.params = ['unit', 'type'];
  module.exports = unit;
  