message: changed the validity of the id argument
diff: @@ -10,7 +10,7 @@ namespace cmdstan {
  arg_id(): int_argument() {
  _name = "id";
  _description = "Unique process identifier";
  - _validity = "id > 0";
  + _validity = "id >= 0";
  _default = "0";
  _default_value = 0;
  _constrained = true;
  @@ -19,7 +19,7 @@ namespace cmdstan {
  _value = _default_value;
  }
  - bool is_valid(int value) { return value > 0; }
  + bool is_valid(int value) { return value >= 0; }
  };
  }
  