code: function _psToFunction(ps) {
      var result = null;
      if (_.isString(ps)) {
          result = function() {
              return ps;
          };
      } else if (_.isFunction(ps)) {
          result = ps;
      } else {
          result = function() {
              return '> ';
          };
      }
  
      return result;
  }
docs: /*!
  Convenience function to convert a potential string or undefined ps string to a function that
  returns the same string.