code: private void addFieldAndGetter(String varName) {
      context.nodeSubtype.addField(NODE, varName)
          .addMethod(newGetter(Strength.STRONG, NODE, varName, Visibility.IMMEDIATE))
          .addMethod(newSetter(NODE, varName, Visibility.IMMEDIATE));
    }
docs: Adds a simple field, accessor, and mutator for the variable.