我正试图创建一个类的对象，只使用这个类的名称：
public interface Foo {
}
public class Bar implements Foo {
}
[...]
Class<Foo> c = Class.forName("com.XXX.Bar").asSubclass(Foo.class);
Foo foo = c.newInstance();
编译器说：
incompatible types found :
java.lang.Class<capture#47 of ? extends com.XXX.Foo>
required: java.lang.Class<com.XXX.Foo>
这里怎么了？
由于c是一个某些类，它扩展了Foo，因此应该使用<；？在代码中表达它；？扩展>语法：
Class<? extends Foo> c = Class.forName("com.XXX.Bar").asSubclass(Foo.class);
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