code: private void parseVariableDeclaration() {
          Variable var = new Variable();
          var.setName(tokenizer.consume().getContents());
          tokenizer.consumeExpectedSymbol(":");
          var.setValue(parseExpression(true));
          if (tokenizer.current().isSymbol("!") && tokenizer.next().hasContent("default")) {
              var.setDefaultValue(true);
              tokenizer.consume();
              tokenizer.consume();
          }
          result.addVariable(var);
          tokenizer.consumeExpectedSymbol(";");
      }
docs: /*
  Parses a variable declaration in form of "$variable: value;" or "$variable: value !default;"