code: FieldRef getCurrentCalleeField() {
      FieldRef local = currentCalleeField;
      if (local == null) {
        local =
            currentCalleeField =
                FieldRef.createField(owner, CURRENT_CALLEE_FIELD, CompiledTemplate.class);
      }
      return local;
    }
docs: Returns the field that holds the current callee template.
  
  <p>Unlike normal variables the VariableSet doesn't maintain responsibility for saving and
  restoring the current callee to a local.