def <<(record)
      load
      record.save! if record.new?
      result = true
      result = false if include?(record)
      @owner.update_association_cache_for(@association, record, :add)
      record.update_association_cache_for(record.associations.find!(@owner).link_field, @owner, :add)
      result && self
    end
def <<(record)
      load
      record.save! if record.new?
      result = true
      result = false if include?(record)
      @owner.update_association_cache_for(@association, record, :add)
      record.update_association_cache_for(record.associations.find!(@owner).link_field, @owner, :add)
      result && self
    end
Add +records+ to this association, saving any unsaved records before adding them.
 Returns +self+ so method calls may be chained.
 Be sure to call save on the association to commit any association changes