Explain Hash.classify-list :&as argument

doc/Type/Hash.pod6

@@ -379,6 +379,19 @@ must have the same number of elements, or the method will throw an exception.
 This restriction exists to avoid conflicts when the same key is a
 leaf of one value's classification but a node of another value's classification.
 
+=head3 C<:&as> value modifier
+
+If C<:&as> L«C<Callable>|/type/Callable» argument is specified, it will be
+called once per each item of C<@list>, with the value as the argument, and
+its return value will be used instead of the original C<@list>'s item:
+
+    say % .classify-list: :as{"Value is $_"}, { $_ %% 2 ?? 'even' !! 'odd' }, ^5;
+    # OUTPUT (slightly altered manually, for clarity):
+    # {
+    #     even => ['Value is 0', 'Value is 2', 'Value is 4'],
+    #     odd  => ['Value is 1', 'Value is 3']
+    # }
+
 =head2 method categorize-list
 
 Defined as: