Docs: .subsequent and .preceding

lib/paper_trail/version_concern.rb

@@ -56,8 +56,13 @@ def not_creates
         where 'event <> ?', 'create'
       end
 
-      # Expects `obj` to be an instance of `PaperTrail::Version` by default,
-      # but can accept a timestamp if `timestamp_arg` receives `true`
+      # Returns versions after `obj`.
+      #
+      # @param obj - a `Version` or a timestamp
+      # @param timestamp_arg - boolean - When true, `obj` is a timestamp.
+      #   Default: false.
+      # @return `ActiveRecord::Relation`
+      # @api public
       def subsequent(obj, timestamp_arg = false)
         if timestamp_arg != true && self.primary_key_is_int?
           return where(arel_table[primary_key].gt(obj.id)).order(arel_table[primary_key].asc)
@@ -67,6 +72,13 @@ def subsequent(obj, timestamp_arg = false)
         where(arel_table[PaperTrail.timestamp_field].gt(obj)).order(self.timestamp_sort_order)
       end
 
+      # Returns versions before `obj`.
+      #
+      # @param obj - a `Version` or a timestamp
+      # @param timestamp_arg - boolean - When true, `obj` is a timestamp.
+      #   Default: false.
+      # @return `ActiveRecord::Relation`
+      # @api public
       def preceding(obj, timestamp_arg = false)
         if timestamp_arg != true && self.primary_key_is_int?
           return where(arel_table[primary_key].lt(obj.id)).order(arel_table[primary_key].desc)
@@ -76,7 +88,6 @@ def preceding(obj, timestamp_arg = false)
         where(arel_table[PaperTrail.timestamp_field].lt(obj)).order(self.timestamp_sort_order('desc'))
       end
 
-
       def between(start_time, end_time)
         where(
           arel_table[PaperTrail.timestamp_field].gt(start_time).