    # File lib/active_record/associations.rb, line 1337
                def construct_association(record, join, row)
                  case join.reflection.macro
                    when :has_many, :has_and_belongs_to_many
                      collection = record.send(join.reflection.name)
                      collection.loaded

                      return nil if record.id.to_s != join.parent.record_id(row).to_s or row[join.aliased_primary_key].nil?
                      association = join.instantiate(row)
                      collection.target.push(association) unless collection.target.include?(association)
                    when :has_one, :belongs_to
                      return if record.id.to_s != join.parent.record_id(row).to_s or row[join.aliased_primary_key].nil?
                      association = join.instantiate(row)
                      record.send("set_#{join.reflection.name}_target", association)
                    else
                      raise ConfigurationError, "unknown macro: #{join.reflection.macro}"
                  end
                  return association
                end