传递给属性的JAXB对象未编组

Question

我已经使用JAXB生成了XML

def plot_city(city_name, data):
    """ generate plot for one city """

   measures = {
        'petal width (cm)': 'tab:orange',
        'sepal width (cm)': 'tab:blue',
    }

    line_styles = {
        'before': '--',
        'after': '-',
    }

    fig, ax = plt.subplots(figsize=(12, 9))

    for measure, colour in measures.items():
        for period, group in data.groupby('period'):
            sns.distplot(
                ax=ax,
                a=group[measure], 
                hist=False, 
                label=f'petal: {period}', 
                color=colour,
                kde_kws={'linestyle':line_styles[period]}
            )

    ax.set_title(city_name, fontsize=24)
    ax.set_xlabel('width (cm)', fontsize=18)
    plt.legend(fontsize=18) 

    return fig


for city_name, data in df.groupby('city'):
    fig = plot_city(city_name, data)
    fig.savefig(f'./{city_name}.png', bbox_inches='tight')
    plt.show()

当我进行解组时，仅正确创建了最后一个CHILD。所有其他均为空。我不知道为什么会这样。我怀疑问题是对象SIM作为属性传递。

这是它的配置方式：

 <relationships>
        <relationship>
            <id>1</id>
            <type>NEUTRAL</type>
            <current>false</current>
            <children>
                <child sim="1" isAdopted="false"/>
            </children>
        </relationship>
        <relationship>
            <id>2</id>
            <type>NEUTRAL</type>
            <current>false</current>
            <children>
                <child sim="2" isAdopted="false"/>
            </children>
        </relationship>
        <relationship>
            <id>4</id>
            <type>LOVE</type>
            <current>true</current>
            <simLeft>2</simLeft>
            <simRight>1</simRight>
            <children>
                <child sim="3" isAdopted="false"/>
            </children>
        </relationship>

儿童班：

@XmlElementWrapper(name = "children")
@XmlElements({@XmlElement(name = "child", type = Child.class)})
private ObservableList<Child> children = FXCollections.observableArrayList();