  Single

  First

    red        green
         blue       
    red        green
    

    Second

           blue       
      red        green
           blue       
      

      Nested

        red        green       blue              blue       
             blue         red        green  red        green
        red        green       blue              blue       
                                                            
             blue         red        green       blue       
        red        green       blue         red        green
             blue         red        green       blue       
                                                            
        red        green       blue              blue       
             blue         red        green  red        green
        red        green       blue              blue       
                                                            
        
