code: function Approximate() {
  
    if(arguments.length > 0) {
  
      if(arguments[0].length < 1 || arguments[0].charAt(0) != 'A') {
        throw new Error('Invalid Approximate Date');
      }
      try {
        Simple.call(this, arguments[0].substr(1));
      } catch(e) {
        throw new Error(e.message+' in Approximate Date');
      }
    } else {
      Simple.call(this);
    }
  }
docs: An approximate GedcomX Date.
  Inherits from Simple.