@Override
      public void visitReferenceExpression(final @NotNull PsiReferenceExpression expression) {
        super.visitReferenceExpression(expression);
        final PsiElement resolved = expression.resolve();
        if (resolved instanceof PsiLocalVariable) {
          final String var = ((PsiLocalVariable)resolved).getName();
          for (PsiVariable variable : outputVariables) {
            if (Comparing.strEqual(variable.getName(), var)) {
              vars.add((PsiLocalVariable)resolved);
              break;
            }
          }
        }
      }
@Override
      public void visitReferenceExpression(final @NotNull PsiReferenceExpression expression)