code: public static boolean equalsNormalizedOnSystem(final String filename1, final String filename2) {
          return equals(filename1, filename2, true, IOCase.SYSTEM);
      }
docs: Checks whether two filenames are equal after both have been normalized
  and using the case rules of the system.
  <p>
  Both filenames are first passed to {@link #normalize(String)}.
  The check is then performed case-sensitive on Unix and
  case-insensitive on Windows.
  
  @param filename1  the first filename to query, may be null
  @param filename2  the second filename to query, may be null
  @return true if the filenames are equal, null equals null
  @see IOCase#SYSTEM