<?php
$filesDir = $files->getFilesDir();
$file = $files->buildFile(function ($fileBuilder) use ($filesDir) {
    $fileBuilder->setPath($filesDir, "tmp/aaa.txt");
});
$file->writeText("hello world", "UTF-8");
$dest = $files->buildFile(function ($fileBuilder) use ($filesDir) {
    $fileBuilder->setPath($filesDir, "tmp/bbb.txt");
});
$console->log($file->renameTo($dest));
$console->log($file->exists());
$console->log($dest->exists());
$file->delete();
$dest->delete();