Varnish: custom header a la cheshire cat (ascii art)

cheshire_cat.vcl

sub headers_x {
## Add after vcl 4.1;
## include "/etc/varnish/ext/cheshire_cat.vcl";
##
## Add after sub vcl_deliver {
## 	call header_smiley;
sub header_smiley {
        set resp.http.xa = "⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀.'\⠀⠀⠀/`.";
        set resp.http.xb = "⠀⠀⠀⠀⠀⠀⠀⠀⠀.'.-.`-'.-.`.";
        set resp.http.xc = "⠀⠀⠀⠀..._:⠀⠀⠀.-.⠀.-.⠀⠀⠀:_...";
        set resp.http.xd = "⠀⠀.'⠀⠀⠀⠀'-.(o )⠀(o ).-'⠀⠀⠀⠀`.";
        set resp.http.xe = "⠀:⠀⠀_⠀⠀⠀⠀_⠀_`~(_)~`_⠀_⠀⠀⠀⠀_⠀⠀:";
        set resp.http.xf = ":⠀⠀/:⠀⠀⠀'⠀.-=_⠀⠀⠀_=-.⠀`⠀⠀⠀;\⠀⠀:";
        set resp.http.xg = ":⠀⠀⠀:|-.._⠀⠀'⠀⠀⠀⠀⠀`⠀⠀_..-|:⠀⠀⠀:";
        set resp.http.xh = "⠀:⠀⠀⠀`:|⠀|`:-:-.-:-:'|⠀|:'⠀⠀⠀:";
        set resp.http.xi = "⠀⠀`.⠀⠀⠀`.|⠀|⠀|⠀|⠀|⠀|⠀|.'⠀⠀⠀.'";
        set resp.http.xj = "⠀⠀⠀⠀`.⠀⠀⠀`-:_|⠀|⠀|_:-'⠀⠀⠀.'";
        set resp.http.xk = "⠀⠀⠀⠀⠀⠀`-._⠀⠀⠀````⠀⠀⠀⠀_.-'";
        set resp.http.xl = "⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀``-------''";
}