`fs.createFile` with mode as unused input

[Martin-Zeithaml]

// cf_test.js
import * as fs from '/zowe/bin/libs/fs';

fs.createFile("./test666.txt", 0o666, "Hello, world!");
fs.createFile("./test600.txt", 0o600, "Hello, world!");
fs.createFile("./test000.txt", 0o000, "Hello, world!");
fs.createFile("./test9999.txt", 9999, "Hello, world!");

$ ./configmgr -script cf_test.js && ls -al test*
-rw-r--r--   1 MARTIN   ZOWEGRP       13 Jun 18 03:20 test000.txt
-rw-r--r--   1 MARTIN   ZOWEGRP       13 Jun 18 03:20 test600.txt
-rw-r--r--   1 MARTIN   ZOWEGRP       13 Jun 18 03:20 test666.txt
-rw-r--r--   1 MARTIN   ZOWEGRP       13 Jun 18 03:20 test9999.txt

It seems the file is open with

zowe-install-packaging/bin/libs/fs.ts

Line 124 in 29f92f9

const file:std.File|null = std.open(path, 'w', errObj);

regardless the mode.

Either remove the mode or implement the mask - I tried the os.umask, but with no effect.