getSyncedCharts() {
    const chartGroups = this.getGroupedCharts()
    let allCharts = [this]
    if (chartGroups.length) {
      allCharts = []
      chartGroups.forEach((ch) => {
        allCharts.push(ch)
      })
    }

    return allCharts
  }
Get all charts in the same "group" (including the instance which is called upon) to sync them when user zooms in/out or pan.