code: public static void createHardLinkMult(File parentDir, String[] fileBaseNames, 
        File linkDir) throws IOException {
      //This is the public method all non-test clients are expected to use.
      //Normal case - allow up to maxAllowedCmdArgLength characters in the cmd
      createHardLinkMult(parentDir, fileBaseNames, linkDir, 
                         getHardLinkCommand.getMaxAllowedCmdArgLength());
    }
docs: Creates hardlinks from multiple existing files within one parent
  directory, into one target directory.
  @param parentDir - directory containing source files
  @param fileBaseNames - list of path-less file names, as returned by
  parentDir.list()
  @param linkDir - where the hardlinks should be put.  It must already exist.
  
  If the list of files is too long (overflows maxAllowedCmdArgLength),
  we will automatically split it into multiple invocations of the
  underlying method.