svoid test_indexOfBytesInFile() {
  File f = createTempFile();
  saveTextFile(f, "bla bla bla blubb bla");
  assertEqualsVerbose(12L, indexOfUTF8StringInFile(f, "blubb"));
  assertEqualsVerbose(-1L, indexOfUTF8StringInFile(f, "blabb"));
}