@CanIgnoreReturnValue
    PatternAsserter matches(String... paths) {
      for (String path : paths) {
        assertTrue(
            "matcher '" + matcher + "' did not match '" + path + "'", matcher.matches(fake(path)));
        if (realMatcher != null) {
          Path realPath = Paths.get(path);
          assertTrue(
              "real matcher '" + realMatcher + "' did not match '" + realPath + "'",
              realMatcher.matches(realPath));
        }
      }
      return this;
    }
Override to return a real matcher for the given pattern.
jimfs/src/test/java/com/google/common/jimfs/AbstractPathMatcherTest.java