let adjacency = Lazy.force neighbs.adjacency in
let total_nodes = List.length adjacency in
if neighbs.shown < total_nodes then begin
(* some more children to show ... *)
let shown_before = neighbs.shown in
neighbs.shown <- min (neighbs.shown + fat_increment) total_nodes;
let adjacency = Lazy.force neighbs.adjacency in
let total_nodes = List.length adjacency in
if neighbs.shown < total_nodes then begin
(* some more children to show ... *)
let shown_before = neighbs.shown in
neighbs.shown <- min (neighbs.shown + fat_increment) total_nodes;