add newBuilder method to the source

[He-Pin]

@FreeBuilder
public interface Bean {
    String getName();
    class Builder extends Bean_Builder {
    }
}

after compile

@FreeBuilder
public interface Bean {
    String getName();

    class Builder extends Bean_Builder {

    }

    static Builder newBuilder() {
        return new Builder();
    }
}

[alicederyn]

Unfortunately, Java does not allow annotation processors to modify existing classes; only generate new ones. But if future Java versions allow it, we'll be on it like a shot!