code: SingleProofreadingError[] getMatches(int numberOfParagraph, int startOfSentencePosition) {
      for (CacheEntry anEntry : entries) {
        if (anEntry.numberOfParagraph == numberOfParagraph && anEntry.startOfSentencePosition == startOfSentencePosition) {
          return anEntry.errorArray;
        }
      }
      return null;
    }
docs: get Proofreading errors from cache