title: How to find private singleton methods
body: <p>I have defined a module <code>Vehicle</code> like such</p>
  
  <pre><code>module Vehicle
    class &lt;&lt;self
      def build
      end
  
      private
  
      def background
      end
    end
  end
  </code></pre>
  
  <p>A call to <code>Vehicle.singleton_methods</code> returns <code>[:build]</code>.</p>
  
  <p>How can I inspect all private singleton methods defined by <code>Vehicle</code>?</p>