docs: function writeFiles(privKey, file, keyMode, cb) {
    // No file name - generate a random one under the system temp dir
    if (!file) {
      file = mkTempFile("_gitane", ".sh")
    }
  
    if (typeof(keyMode) === 'function') {
      cb = keyMode
      keyMode = 0600
    }
  
    var keyfile = mkTempFile("_gitaneid", ".key")
    var keyfileName = keyfile
    if (isWindows) {
      keyfileName = "\"" + keyfile.replace(/\\/g,"\\\\") + "\"";
    }
  
    var data = GIT_SSH_TEMPLATE.replace('$key', keyfileName)
    Step(
        function() {
        fs.writeFile(file, data, this.parallel())
        fs.writeFile(keyfile, privKey, this.parallel())
      },
      function(err) {
        if (err) {
          return cb(err, null)
        }
        // make script executable
        fs.chmod(file, 0755, this.parallel())
        // make key secret
        fs.chmod(keyfile, keyMode, this.parallel())
      },
      function(err) {
        if (err) {
          return cb(err, null)
        }
  
        return cb(null, file, keyfile)
      }
    )
  }