Close waterfall nodes by default.

src/lib/decompositions.ts

@@ -318,8 +318,9 @@ function buildVisibleDecompositions1(
     }
     if (visibleChildren !== undefined) {
       visibleDecomposition.visibleChildren = visibleChildren
-      if (decomposition.open === undefined) {
-        decomposition.open = depth < 1
+      // if ((trunk || depth < 1) && !decomposition.open) {
+      if (trunk && !decomposition.open) {
+        decomposition.open = true
       }
     } else if (decomposition.open) {
       delete decomposition.open