Add examples to #slice and #values_at documentation [ci-skip] (rails#50679)

Author: p8

activemodel/lib/active_model/model.rb

@@ -52,6 +52,10 @@ module Model
     # Returns a hash of the given methods with their names as keys and returned
     # values as values.
     #
+    #   person = Person.new(id: 1, name: "bob")
+    #   person.slice(:id, :name)
+    #   => { "id" => 1, "name" => "bob" }
+    #
     #--
     # Implemented by ActiveModel::Access#slice.
 
@@ -62,6 +66,10 @@ module Model
     #
     # Returns an array of the values returned by the given methods.
     #
+    #   person = Person.new(id: 1, name: "bob")
+    #   person.values_at(:id, :name)
+    #   => [1, "bob"]
+    #
     #--
     # Implemented by ActiveModel::Access#values_at.
   end

activerecord/lib/active_record/core.rb

@@ -569,6 +569,10 @@ def encode_with(coder)
     # Returns a hash of the given methods with their names as keys and returned
     # values as values.
     #
+    #   topic = Topic.new(title: "Budget", author_name: "Jason")
+    #   topic.slice(:title, :author_name)
+    #   => { "title" => "Budget", "author_name" => "Jason" }
+    #
     #--
     # Implemented by ActiveModel::Access#slice.
 
@@ -579,6 +583,10 @@ def encode_with(coder)
     #
     # Returns an array of the values returned by the given methods.
     #
+    #   topic = Topic.new(title: "Budget", author_name: "Jason")
+    #   topic.values_at(:title, :author_name)
+    #   => ["Budget", "Jason"]
+    #
     #--
     # Implemented by ActiveModel::Access#values_at.