docs: function _createParticles(node, count) {
          this._particles = [];
          var options = {
              size: [this.options.particleSize, this.options.particleSize],
              properties: {
                  backgroundColor: this.options.color,
                  borderRadius: '50%'
              }
          };
          for (var i = 0; i < count; i++) {
              var particle = {
                  surface: new Surface(options),
                  mod: new Modifier({})
              };
              this._particles.push(particle);
              node.add(particle.mod).add(particle.surface);
          }
      }