preloaders_for_reflection

# File activerecord/lib/active_record/associations/preloader.rb, line 144
        def preloaders_for_reflection(reflection, records, scope)
          records.group_by { |record| record.association(reflection.name).klass }.map do |rhs_klass, rs|
            preloader_for(reflection, rs).new(rhs_klass, rs, reflection, scope).run
          end
        end