setVisible (visible) {
    const expected = visible === undefined || visible ? 'inline' : 'none'
    const oldDisplay = this.group_.getAttribute('display')
    if (oldDisplay !== expected) {
      this.group_.setAttribute('display', expected)
    }
  }
Set this layer visible or hidden based on 'visible' parameter.
@param {boolean} visible - If true, make visible; otherwise, hide it.
@returns {void}