handleThumbKeyDown (event) {
      let flag = false
      let newValue
      const tenSteps = (this.max - this.min) / 10

      switch (event.key) {
        case 'ArrowLeft':
        case 'ArrowDown':
          newValue = this.actualValue - this.step
          flag = true
          break
        case 'ArrowRight':
        case 'ArrowUp':
          newValue = this.actualValue + this.step
          flag = true
          break
        case 'PageDown':
          newValue = this.actualValue - tenSteps
          flag = true
          break
        case 'PageUp':
          newValue = this.actualValue + tenSteps
          flag = true
          break
        case 'Home':
          newValue = this.min
          flag = true
          break
        case 'End':
          newValue = this.max
          flag = true
          break
        default:
          return
      }

      if (flag) {
        event.preventDefault()
        event.stopPropagation()
      }
      if (this.step) {
        newValue = roundValueToStep(newValue, this.step)
      }
      newValue = clampValue(newValue, this.min, this.max)
      this.updateValue(newValue)

      this.$emit('keydown', event)
    }
Handles SliderThumb keydown event
@param {Event} event