PMD/CPD无法检测到重复的代码

我的maven项目正在正常编译并生成所有报告mvn jxr:jxr site.但我无法找到任何显示重复代码的结果.为了测试这个,我在我的代码中故意引入了重复的代码,如:

@Override
public boolean equals(Object object) {
    // TODO: Warning - this method won't work in the case the id fields are not set
    if (!(object instanceof Address)) {
        return false;
    }
    Address other = (Address) object;
    if ((this.id == null && other.id != null)
      || (this.id != null && !this.id.equals(other.id))) {
        return false;
    }
    if (!(object instanceof Address)) { //Duplicate is here
        return false;
    }
    return true;
}