docs: private void classifyMethod(ExecutableElement method) {
      switch (method.getParameters().size()) {
        case 0:
          classifyMethodNoArgs(method);
          break;
        case 1:
          classifyMethodOneArg(method);
          break;
        default:
          errorReporter.reportError("Builder methods must have 0 or 1 parameters", method);
      }
    }