@Nullable
    private static Integer extractLength(PsiExpression rOperand,
                                         RelationType relation,
                                         int size,
                                         PsiVariable targetBuilder) {
      if (!isStringBuilderLengthCall(rOperand, targetBuilder)) return null;
      LongRangeSet rangeSet = LongRangeSet.point(size).fromRelation(relation);
      if (rangeSet == null || rangeSet.max() != Long.MAX_VALUE) return null;
      long min = rangeSet.min();
      return min > 0 ? (int)(min - 1) : null;
    }
@Nullable
    private static Integer extractLength(PsiExpression rOperand,
                                         RelationType relation,
                                         int size,
                                         PsiVariable targetBuilder)