use for_list in Tree.pm and TreeNode.pm

lib/Biodiverse/Tree.pm

@@ -19,6 +19,7 @@ use POSIX qw /floor ceil/;
 use feature 'refaliasing';
 no warnings 'experimental::refaliasing';
 
+use experimental 'for_list';
 
 use English qw ( -no_match_vars );
 
@@ -527,8 +528,7 @@ sub get_node_length_hash {
 
     my %len_hash;
     my $node_hash = $self->get_node_hash;
-    foreach my $node_name ( keys %$node_hash ) {
-        my $node_ref = $node_hash->{$node_name};
+    foreach my ($node_name, $node_ref) ( %$node_hash ) {
         $len_hash{$node_name} = $node_ref->get_length;
     }
 
@@ -3353,7 +3353,7 @@ sub get_nti_expected_mean {
 
     my $s = $self->get_terminal_element_count;
     my $cb_bnok_one_arg = $self->get_bnok_ratio_callback_one_val(r => $r, s => $s);
-    my $cb_bnok_two_arg = $self->get_bnok_ratio_callback_two_val(r => $r, s => $s);
+    # my $cb_bnok_two_arg = $self->get_bnok_ratio_callback_two_val(r => $r, s => $s);
 
     \my %tip_count_cache
       = $self->get_cached_value_dor_set_default_aa (NODE_TIP_COUNT_CACHE => {});
@@ -3363,8 +3363,7 @@ sub get_nti_expected_mean {
 
     my $sum;
     my $node_hash = $self->get_node_hash;
-    foreach my $name (keys %$node_hash) {
-        my $node = $node_hash->{$name};
+    foreach my ($name, $node) (%$node_hash) {
         my $se
           = $tip_count_cache{$name}
             //= $node->get_terminal_element_count;

lib/Biodiverse/TreeNode.pm

@@ -1,12 +1,14 @@
 package Biodiverse::TreeNode;
-use 5.022;
+use 5.036;
 use strict;
 use warnings;
 no warnings 'recursion';
 
 use feature 'refaliasing';
 no warnings 'experimental::refaliasing';
 
+use experimental 'for_list';
+
 use English qw ( -no_match_vars );
 use Ref::Util qw { :all };
 
@@ -2769,8 +2771,8 @@ sub _get_len_sum_by_tip_count_hash {
     $hash->{$self->get_terminal_element_count} += $self->get_length;
     foreach my $child ($self->get_children) {
         my $ch_hash = $child->_get_len_sum_by_tip_count_hash;
-        foreach my $tc (keys %$ch_hash) {
-            $hash->{$tc} += $ch_hash->{$tc};
+        foreach my ($tc, $val) (%$ch_hash) {
+            $hash->{$tc} += $val;
         }
     }
     $self->set_cached_value($cache_key => $hash);