@NotNull
  public static Set<Pair<PsiElement, String>> searchStringExpressions(@NotNull final PsiMethod psiMethod,
                                                                      @NotNull SearchScope searchScope,
                                                                      int expNum) {
    Set<Pair<PsiElement, String>> pairs = new HashSet<>();
    for (PsiCall methodCallExpression : searchMethodCalls(psiMethod, searchScope)) {
      PsiExpressionList argumentList = methodCallExpression.getArgumentList();
      if (argumentList == null) continue;
      final PsiExpression[] expressions = argumentList.getExpressions();
      if (expressions.length > expNum) {
        final PsiExpression expression = expressions[expNum];
        Pair<PsiElement, String> pair = evaluateExpression(expression);
        if (pair != null) {
          pairs.add(pair);
        }
      }
    }

    return pairs;
  }
@NotNull
  public static Set<Pair<PsiElement, String>> searchStringExpressions(@NotNull final PsiMethod psiMethod,
                                                                      @NotNull SearchScope searchScope,
                                                                      int expNum)