@NotNull
  public BetterPrefixMatcher improve(CompletionResult result) {
    int degree = RealPrefixMatchingWeigher.getBestMatchingDegree(result.getLookupElement(), result.getPrefixMatcher());
    if (degree <= myMinMatchingDegree) return this;

    return createCopy(myOriginal, degree);
  }
@NotNull
  public BetterPrefixMatcher improve(CompletionResult result)