@function _partition-map-by-key($map, $function) {
  $partitioned-map-keys: _partition-list(
    map-keys($map),
    $function
  );

  $a: _limit-map-keys($map, nth($partitioned-map-keys, 1));
  $b: _limit-map-keys($map, nth($partitioned-map-keys, 2));

  @return (
    $a,
    $b
  );
}