How to use the @pluralsight/ps-design-system-icon.sizes.medium function in @pluralsight/ps-design-system-icon

const mapIconSize = props => {
  const btnToIconSizes = {
    [vars.sizes.xSmall]: iconSizes.small,
    [vars.sizes.small]: iconSizes.medium,
    [vars.sizes.medium]: iconSizes.medium,
    [vars.sizes.large]: iconSizes.medium
  }
  return btnToIconSizes[props.size]
    ? btnToIconSizes[props.size]
    : iconSizes.medium
}

const ItemIcon = props => {
  return (
    <div>
      {React.cloneElement(props.children, { size: iconSizes.medium })}
    </div>
  )
}
ItemIcon.propTypes = {

const mapIconSize = props => {
  const btnToIconSizes = {
    [vars.sizes.xSmall]: iconSizes.small,
    [vars.sizes.small]: iconSizes.medium,
    [vars.sizes.medium]: iconSizes.medium,
    [vars.sizes.large]: iconSizes.medium
  }
  return btnToIconSizes[props.size]
    ? btnToIconSizes[props.size]
    : iconSizes.medium
}

const isPrev = props.direction === Control.directions.prev
  const visible = isPrev ? activePage > 0 : activePage !== pageCount - 1

  const IconCaret = isPrev ? CaretLeftIcon : CaretRightIcon
  const handleClick = combineFns(isPrev ? prev : next, props.onClick)

  return (
    <li>
      <button aria-label="{isPrev">
        
      </button>
    </li>
  )
}