How to use the @instructure/ui-dom-utils.isActiveElement function in @instructure/ui-dom-utils

handleKeyDown = (event) => {
    const {
      filterText,
      selectedOption,
      selectedOption: { length }
    } = this.state

    // If the user pressed backspace while focusing on input, input is emtpy and there's selectedOptions
    if (
      (event.key === 'Backspace' || event.key === 'Delete') &&
      length > 0 &&
      filterText === '' &&
      isActiveElement(this._input)
    ) {
      this.dismiss(event, selectedOption[length - 1])
    }

    this.props.onKeyDown(event)
  }

event.preventDefault()
    return
  }

  // Account for a changing tabindex of the active element
  // (a case that happens with Menu for KO a11y)
  if (containsActiveElement(element)) {
    const activeElement = getActiveElement()
    if (tabbable.indexOf(activeElement) === -1) {
      tabbable.push(activeElement)
    }
  }

  const finalTabbable = tabbable[event.shiftKey ? 0 : tabbable.length - 1]
  const leavingFinalTabbable = (
    isActiveElement(finalTabbable) ||
    // handle immediate shift+tab after opening with mouse
    isActiveElement(node) ||
    // already left final tabbable
    !containsActiveElement(element)
  )

  if (!leavingFinalTabbable) return

  if (typeof onLeavingFinalTabbable === 'function') {
    onLeavingFinalTabbable()
    return
  }

  event.preventDefault()
  const target = tabbable[event.shiftKey ? tabbable.length - 1 : 0]
  target.focus()

}

  // Account for a changing tabindex of the active element
  // (a case that happens with Menu for KO a11y)
  if (containsActiveElement(element)) {
    const activeElement = getActiveElement()
    if (tabbable.indexOf(activeElement) === -1) {
      tabbable.push(activeElement)
    }
  }

  const finalTabbable = tabbable[event.shiftKey ? 0 : tabbable.length - 1]
  const leavingFinalTabbable = (
    isActiveElement(finalTabbable) ||
    // handle immediate shift+tab after opening with mouse
    isActiveElement(node) ||
    // already left final tabbable
    !containsActiveElement(element)
  )

  if (!leavingFinalTabbable) return

  if (typeof onLeavingFinalTabbable === 'function') {
    onLeavingFinalTabbable()
    return
  }

  event.preventDefault()
  const target = tabbable[event.shiftKey ? tabbable.length - 1 : 0]
  target.focus()
}

get focused () {
    return isActiveElement(this._button)
  }

get focused () {
    return isActiveElement(this._link)
  }

get focused () {
    return isActiveElement(this._button)
  }

get focused () {
    return isActiveElement(this._container)
  }

get focused () {
    return isActiveElement(this._button)
  }

get focused () {
    return this._input && isActiveElement(this._input)
  }

get focused () {
    return isActiveElement(this._container)
  }