code: public static boolean equalsOnSystem(String filename1, String filename2) {
          return equals(filename1, filename2, false, IOCase.SYSTEM);
      }
docs: Checks whether two filenames are equal using the case rules of the system.
  <p>
  No processing is performed on the filenames other than comparison.
  The check is 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