asda?‰PNG

   
IHDR   ?   f   ??C1   
sRGB ??é   gAMA  ±?üa   	pHYs  ?  ?
?o¨d  GIDATx^íüL”÷e÷Y?a?("Bh?_ò???￠§?q5k?*:t0A-o??￥]VkJ￠M??f?±8\k2íll￡1]q?ù???T

/* Collapse all edges with same group attribute into a single edge */
BEG_G {
  int seen[string];
  $O = $;            // Use the input graph as output.
}
E {
  if (collapse == "") return;          // If no collapse, ignore.
  if (seen[collapse]) delete ($G, $);  // If already seen an edge with this collapse value, 
                                       // delete the edge.
  else seen[collapse] = 1;             // Else mark collapse value as seen and keep edge.
}