无法使用 retofit 解析对 kotlin 数据类的 xml 响应

问：

我正在尝试调用给我xml响应的rest api。我正在使用 simplexml 转换器工厂的改造将 xml 解析为 kotlin 数据 clas。下面是来自 api 的 xml 响应：

<category>
    <api-version>1.0</api-version>
    <books>
        <list>
            <result>
                <author>Hello1</author>
                <brief>Hii</brief>
            </result>
            <result>
                <author>Hello2</author>
                <brief>Hii2</brief>
            </result>
        </list>
    </books>
</category> 

下面是我的 Kotlin 数据类

data class CategoryResponseModel(
        @field:Element(name = "api-version", required = false)
        @param:Element(name = "api-version", required = false)
        val apiVersion: String? = null,

        @field:Element(name = "books", required = false)
        @param:Element(name = "books", required = false)
        val books: Books? = null
)

data class Books(
        @field:Element(name = "list", required = false)
        @param:Element(name = "list", required = false)
        val list: BookList? = null
)

@Root(name = "list")
data class BookList(
        @field:Element(name = "result", required = false)
        @param:Element(name = "result", required = false)
        val result: List<BookSearchResult>? = null,
)

data class BookSearchResult(

        @field:Element(name = "author", required = false)
        @param:Element(name = "author", required = false)
        val author: String? = null,

        @field:Element(name = "brief", required = false)
        @param:Element(name = "brief", required = false)
        val briefSynopsis: String? = null,
)

但是我收到改造SimpleXML的错误org.simpleframework.xml.core.ElementException: Element 'result[1]/author[1]' does not have a match in class BookList