docs: public void autoAssign(ProxyField proxyField, RuleContext ruleContext)
      {
          // Count the excludes left and if only 1 then assign this value.
          // TODO: work out what should happen if a later rule excludes this value
          ChoiceBase lastChoice = findLastChoice(proxyField);
          if (lastChoice != null)
          {
              Object value = proxyField.getPropertyMetadata().convertFromString(lastChoice.getKey().toString());
              s_log.debug("{}auto-assign: {} {}",new Object[]{m_indenter,proxyField,value});
              assign(getRuleProxyField(proxyField),value,ruleContext,true);
          }        
      }