func visit(t testing.TB, x *assert.Assertions, visited *set.SortedSet, node Node) {
errors.Logf("DEBUG", "visiting %v", node)
if visited.Has(node.Pattern()) {
return
}
visited.Add(node.Pattern())
checkNode(t, x, node)
kids, err := node.Children()
if err != nil {
t.Fatal(err)
}
for _, kid := range kids {
if !visited.Has(kid.Pattern()) {
visit(t, x, visited, kid.(Node))
}
}
}
