/**
* make a hex sha1 string
* @param {string} content some content
* @return {string} the hex result
*/
function makeSha1Hex (content) {
  return byteToHexString(Utilities.computeDigest(Utilities.DigestAlgorithm.SHA_1, content));
}
/**
* convert an array of bytes to a hex string
* @param {Array.byte} bytes the byte array to convert
* @return {string} the hex encoded string
*/
function byteToHexString (bytes) {
  return bytes.reduce(function (p,c) {
    return p += padLeading ((c < 0 ? c+256 : c).toString(16), 2 );
  },'');
}
/**
* pad leading part of string
* @param {string} stringtoPad the source string
* @param {number} targetLength what the final string length should be
* @param {string} padWith optional what to pad with - default "0"
* @return {string} the padded string
*/
function padLeading (stringtoPad , targetLength , padWith) {
  return (stringtoPad.length < targetLength ? Array(1+targetLength-stringtoPad.length).join(padWith | "0") : "" ) + stringtoPad ;
}
/**
* get base64 encoded data as a string
* @param {string} b64 as a string
* @return {string} decoded as as string
*/
function b64ToString ( b64) {
  return Utilities.newBlob(Utilities.base64Decode(result.content)).getDataAsString();
}