function getA11yStatusMessage({isOpen, resultCount, previousResultCount}) {
  if (!isOpen) {
    return ''
  }

  if (!resultCount) {
    return 'No results are available.'
  }

  if (resultCount !== previousResultCount) {
    return `${resultCount} result${
      resultCount === 1 ? ' is' : 's are'
    } available, use up and down arrow keys to navigate. Press Enter key to select.`
  }

  return ''
}
Default implementation for status message. Only added when menu is open.
Will specify if there are results in the list, and if so, how many,
and what keys are relevant.

@param {Object} param the downshift state and other relevant properties
@return {String} the a11y status message