@Test(timeout = 1000)
 public void testIDWhichIsDefined() {
   final PrimaryExpression expression = this.factory.createPrimaryExpression();
   expression.setIdent("FOO");
   this.definitionTable.add("FOO", "1");
   Assert.assertEquals(ExpressionLongVisitor.TRUE, this.evaluater.walkTo(expression));
 }
 @Test(timeout = 1000)
 public void testIDWhichIsEmpty() {
   final PrimaryExpression expression = this.factory.createPrimaryExpression();
   expression.setIdent("FOO");
   Assert.assertEquals(ExpressionLongVisitor.FALSE, this.evaluater.walkTo(expression));
 }