code: function ForceAtlas2() {
          //-------------
          // Configs
  
          // If auto settings is true
          //  barnesHutOptimize,
          //  barnesHutTheta,
          //  scaling,
          //  jitterTolerence
          // Will be set by the system automatically
          //  preventOverlap will be set false
          //  if node size is not given
          this.autoSettings = true;
  
          // Barnes Hut
          // http://arborjs.org/docs/barnes-hut
          this.barnesHutOptimize = true;
          this.barnesHutTheta = 1.5;
  
          // Force Atlas2 Configs
          this.repulsionByDegree = true;
  
          this.linLogMode = false;
  
          this.strongGravityMode = false;
          this.gravity = 1.0;
  
          this.scaling = 1.0;
  
          this.edgeWeightInfluence = 1.0;
          this.jitterTolerence = 0.1;
  
          // TODO
          this.preventOverlap = false;
          this.dissuadeHubs = false;
  
          //
          this.rootRegion = new Region();
          this.rootRegion.centerOfMass = vec2.create();
  
          this.nodes = [];
  
          this.edges = [];
  
          this.bbox = new Float32Array(4);
  
          this.gravityCenter = null;
  
          this._massArr = null;
  
          this._swingingArr = null;
  
          this._sizeArr = null;
  
          this._globalSpeed = 0;
      }
docs: **************************
  Class: ForceStlas2
  *************************