class TreeBalancer {
  constructor(x, y, crossY) {
    this.x = x;
    this.y = y;
    this.r = 10;
    this.crossY = crossY;
    this.color = 'green';
  }

  draw() {
    d3.select(getId(balancerGroupId)).append('circle').attr('r', this.r)
    .attr('cx', this.x).attr('cy', this.y).style('fill', this.color);
  }
}
