private static void assertGlobRegexIs(String glob, String regex, String separators) {
    assertEquals(regex, GlobToRegex.toRegex(glob, separators));
    Pattern.compile(regex); // ensure the regex syntax is valid
  }
Tests for {@link PathMatcher} instances created by {@link GlobToRegex}.

@author Colin Decker
jimfs/src/test/java/com/google/common/jimfs/RegexGlobMatcherTest.java