import com.sun.xml.internal.ws.api.model.wsdl.WSDLExtension; //导入依赖的package包/类
public final <T extends WSDLExtension> Iterable<T> getExtensions(Class<T> type) {
    // TODO: this is a rather stupid implementation
    List<T> r = new ArrayList<T>(extensions.size());
    for (WSDLExtension e : extensions) {
        if(type.isInstance(e))
            r.add(type.cast(e));
    }
    return r;
}
 

import com.sun.xml.internal.ws.api.model.wsdl.WSDLExtension; //导入依赖的package包/类
public <T extends WSDLExtension> T getExtension(Class<T> type) {
    for (WSDLExtension e : extensions) {
        if(type.isInstance(e))
            return type.cast(e);
    }
    return null;
}
 

import com.sun.xml.internal.ws.api.model.wsdl.WSDLExtension; //导入依赖的package包/类
public void addExtension(WSDLExtension ex) {
    if(ex==null)
        // I don't trust plugins. So let's always check it, instead of making this an assertion
        throw new IllegalArgumentException();
    extensions.add(ex);
}