@Override
      public void visitReferenceExpression(@NotNull PsiReferenceExpression expression) {
        super.visitReferenceExpression(expression);
        if (expression.getQualifierExpression() != null) {
          // optimization
          // references to parameters are never qualified
          return;
        }
        final PsiElement target = expression.resolve();
        if (!(target instanceof PsiParameter parameter)) {
          return;
        }
        parameters.remove(parameter);
        if (parameters.isEmpty()) {
          stopWalking();
        }
      }
@Override
      public void visitReferenceExpression(@NotNull PsiReferenceExpression expression)