Fill in headers on request RestFul Jersey

I have a RestFul service which should receive a% custom header , the service works correctly, the service client believes it with the Netbeans assistant but I do not know how to fill the% custom% co, this is the client RestFul

public class AlbumServiceClient {

    private WebTarget webTarget;
    private Client client;
    private static final String BASE_URI = "http://localhost:38383/MusicRest/musicApi";

    public AlbumServiceClient() {
        client = javax.ws.rs.client.ClientBuilder.newClient();
        webTarget = client.target(BASE_URI).path("album");
    }

    public <T> T getAlbumes(Class<T> responseType) throws ClientErrorException {
        WebTarget resource = webTarget;
        resource = resource.path("getList");
        return resource.request(javax.ws.rs.core.MediaType.APPLICATION_XML).get(responseType);
    }

    public void close() {
        client.close();
    }

}