code: function(){
  
              var list
                  ,len
                  ,i
                  ,hole
                  ,bound
                  ,boundVal
                  ,left
                  ,leftVal
                  ,axis
                  ;
  
              // for each axis...
              for ( var xyz = 0; xyz < maxDof; ++xyz ){
  
                  // get the intervals for that axis
                  list = this.intervalLists[ xyz ];
                  i = 0;
                  len = list.length;
                  axis = xyz;
  
                  // for each interval bound...
                  while ( (++i) < len ){
  
                      // store bound
                      bound = list[ i ];
                      boundVal = bound.val.get( axis );
                      hole = i;
  
                      left = list[ hole - 1 ];
                      leftVal = left && left.val.get( axis );
  
                      // while others are greater than bound...
                      while (
                          hole > 0 &&
                          (
                              leftVal > boundVal ||
                              // if it's an equality, only move it over if
                              // the hole was created by a minimum
                              // and the previous is a maximum
                              // so that we detect contacts also
                              leftVal === boundVal &&
                              ( left.type && !bound.type )
                          )
                      ) {
  
                          // move others greater than bound to the right
                          list[ hole ] = left;
                          hole--;
                          left = list[ hole - 1 ];
                          leftVal = left && left.val.get( axis );
                      }
  
                      // insert bound in the hole
                      list[ hole ] = bound;
                  }
              }
          }
docs: internal
  SweepPruneBehavior#sortIntervalLists()
  
  Simple insertion sort for each axis