code: function _default(input) {
    var parsed_input = parseInput(input);
  
    if (parsed_input !== null) {
      var value = parsed_input.value,
          unit = parsed_input.unit;
      return relative_time_units[unit] * value;
    }
  
    return null;
  }
docs: Parse simple relative time in human readable format to milliseconds.
  @name parseRelativeTime
  @param {string} input - Human readable format of relative time
  @returns {null | number}
  @example
  parseRelativeTime('2 days');  // --> 172800000
  parseRelativeTime('-2 days');
  parseRelativeTime('in 2 days');
  parseRelativeTime('2 days ago');