int getComplexity(@Nullable PsiExpression expression) {
    if (expression == null) {
      return 0;
    }

    int complexity = myCache.get(expression);
    if (complexity < 0) {
      complexity = calculateComplexity(expression);
      myCache.put(expression, complexity);
    }
    return complexity;
  }
int getComplexity(@Nullable PsiExpression expression)