function test_post_gallery_images() {
    $ids1      = array();
    $ids1_srcs = array();
    foreach ( range( 1, 3 ) as $i ) {
      $attachment_id = self::factory()->attachment->create_object(
        "image$i.jpg",
        0,
        array(
          'post_mime_type' => 'image/jpeg',
          'post_type'      => 'attachment',
        )
      );
      $metadata      = array_merge( array( 'file' => "image$i.jpg" ), $this->img_meta );
      wp_update_attachment_metadata( $attachment_id, $metadata );
      $ids1[]      = $attachment_id;
      $ids1_srcs[] = 'http://' . WP_TESTS_DOMAIN . '/wp-content/uploads/' . "image$i.jpg";
    }

    $ids2      = array();
    $ids2_srcs = array();
    foreach ( range( 4, 6 ) as $i ) {
      $attachment_id = self::factory()->attachment->create_object(
        "image$i.jpg",
        0,
        array(
          'post_mime_type' => 'image/jpeg',
          'post_type'      => 'attachment',
        )
      );
      $metadata      = array_merge( array( 'file' => "image$i.jpg" ), $this->img_meta );
      wp_update_attachment_metadata( $attachment_id, $metadata );
      $ids2[]      = $attachment_id;
      $ids2_srcs[] = 'http://' . WP_TESTS_DOMAIN . '/wp-content/uploads/' . "image$i.jpg";
    }

    $ids1_joined = join( ',', $ids1 );
    $ids2_joined = join( ',', $ids2 );

    $blob    = <<<BLOB
[gallery ids="$ids1_joined"]

[gallery ids="$ids2_joined"]
BLOB;
    $post_id = self::factory()->post->create( array( 'post_content' => $blob ) );
    $srcs    = get_post_gallery_images( $post_id );
    $this->assertEquals( $srcs, $ids1_srcs );
  }