#vulnerable code 
                              public <PSI> Iterator<Match> findAll(PSI target) throws FindFailed {
    lastMatches = null;
    Image img = null;
    String targetStr = target.toString();
    if (target instanceof String) {
      targetStr = targetStr.trim();
    }
    while (true) {
      try {
        if (autoWaitTimeout > 0) {
          RepeatableFindAll rf = new RepeatableFindAll(target);
          rf.repeat(autoWaitTimeout);
          lastMatches = rf.getMatches();
        } else {
          lastMatches = doFindAll(target, null);
        }
      } catch (Exception ex) {
        if (ex instanceof IOException) {
          if (handleImageMissing(img)) {
            continue;
          }
        }
        throw new FindFailed(ex.getMessage());
      }
      if (lastMatches != null) {
        return lastMatches;
      }
      if (!handleFindFailed(img)) {
        return null;
      }
    }
  } 
                            #location 28 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                              public <PSI> Iterator<Match> findAll(PSI target) throws FindFailed {
    lastMatches = null;
    Image img = null;
    String targetStr = target.toString();
    if (target instanceof String) {
      targetStr = targetStr.trim();
    }
    while (true) {
      try {
        if (autoWaitTimeout > 0) {
          RepeatableFindAll rf = new RepeatableFindAll(target);
          rf.repeat(autoWaitTimeout);
          lastMatches = rf.getMatches();
        } else {
          lastMatches = doFindAll(target, null);
        }
      } catch (Exception ex) {
        if (ex instanceof IOException) {
          if (handleImageMissing(img, false)) {
            continue;
          }
        }
        throw new FindFailed(ex.getMessage());
      }
      if (lastMatches != null) {
        return lastMatches;
      }
      if (!handleFindFailed(img)) {
        return null;
      }
    }
  }