code: function() {
              var stable = [];
              for (var i=0;i<physicsSimulators.length; i++) {
                  stable.push(physicsSimulators[i].step());
              }
              // Check if all simulators are stable
              //console.log(stable);
              for (i=0;i<stable.length;i++) {
                  if (!stable[i]) {
                      return false
                  }
              }
              return true;
          }
docs: Do one step of iterative layout calculation
  Return true is the current layout is stable