first                                                                                                                   big container 
                                                                                                                                                               
                                                                                                                                                           foo1
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                         second box                                                                                                                            
                                                                                                                                                               
                                                                                                                                                           foo2
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                         third                                                                                                                                 
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                           foo3