code: function encodeDouble(value) {
  	if (value === null) {
  		return values.NULL;
  	} else if (!isNaN(value)) {
  		return value + "";
  	} else {
  		throw new Error('Invalid double value "' + value + '"');
  	}
  }
docs: Encodes a float according to the ARI protocol.
  
  @param {Number} value input
  @return {String} output
  @private