How do I hide only the window title, while keeping window buttons, from title bar?

There is an option to use the icons-and-text task manager widget, which makes the window title in the title bar redundant. The same is applicable when somebody uses the window title applet to create a macOS/Unity like layout.

Everything in the title bar can be removed, but not the window title. If somebody wants to remove the window title but keep the buttons, how can this be done?

At the moment there is no way for you to do this.