preload

# File activerecord/lib/active_record/associations/preloader/singular_association.rb, line 8
        def preload(preloader)
          associated_records_by_owner(preloader).each do |owner, associated_records|
            record = associated_records.first

            association = owner.association(reflection.name)
            association.target = record
            association.set_inverse_instance(record) if record
          end
        end