code: function( data ){
  
              var body = data.body
                  ,list
                  ,minmax
                  ,trackedList = this.tracked
                  ,tracker
                  ,count
                  ;
  
              for ( var i = 0, l = trackedList.length; i < l; ++i ){
  
                  tracker = trackedList[ i ];
  
                  if ( tracker.body === body ){
  
                      // remove the tracker at this index
                      trackedList.splice(i, 1);
  
                      for ( var xyz = 0; xyz < maxDof; ++xyz ){
  
                          count = 0;
                          list = this.intervalLists[ xyz ];
  
                          for ( var j = 0, m = list.length; j < m; ++j ){
  
                              minmax = list[ j ];
  
                              if ( minmax === tracker.interval.min || minmax === tracker.interval.max ){
  
                                  // remove interval from list
                                  list.splice(j, 1);
                                  j--;
                                  l--;
  
                                  if (count > 0){
                                      break;
                                  }
  
                                  count++;
                              }
                          }
                      }
  
                      break;
                  }
              }
          }
docs: internal
  SweepPruneBehavior#untrackBody( data )
  - data (Object): Event data
  
  Event callback to remove body from list of those tracked