code: public static MethodHandle defaultInvoker( Method method )
      {
          if ( !method.isDefault() )
          {
              throw new IllegalArgumentException( "Not a default method: " + method );
          }
          try
          {
              return LOOKUP.unreflectSpecial( method, method.getDeclaringClass() );
          }
          catch ( IllegalAccessException e )
          {
              throw new RuntimeException( "Reflection failed.", e );
          }
      }
docs: Returns a method handle that invoke a default method of an interface.
  
  @param method the (default) method to get a method handle for.
  @return a method handle that invokes the specific default method.