• active_record/relation/from_clause
• active_record/relation/query_attribute
• active_record/relation/where_clause
• active_support/core_ext/array/wrap

• 模組 ActiveModel
• 模組 ActiveRecord
• 模組 ActiveRecord::Associations
• 模組 ActiveRecord::QueryMethods
• 模組 Arel
• 類別 ActiveRecord::QueryMethods::WhereChain
• 類別 ActiveRecord::Relation