code: void expectITemplateArraySupertype(Node n, JSType type, String msg) {
      if (!getNativeType(I_TEMPLATE_ARRAY_TYPE).isSubtypeOf(type)) {
        mismatch(n, msg, type, I_TEMPLATE_ARRAY_TYPE);
      }
    }
docs: Expect the type to be an ITemplateArray or supertype of ITemplateArray.