@Nullable
      private static PsiExpression extractDelimiter(@NotNull PsiAssignmentExpression assignmentExpression) {
        PsiExpression expression = assignmentExpression.getRExpression();
        if (expression == null) return null;
        Object constantExpression = ExpressionUtils.computeConstantExpression(expression);
        if (!(constantExpression instanceof String)) return null;
        return expression;
      }
@Nullable
      private static PsiExpression extractDelimiter(@NotNull PsiAssignmentExpression assignmentExpression)