delete_through_records

# File activerecord/lib/active_record/associations/has_many_through_association.rb, line 128
        def delete_through_records(through, records)
          if through_reflection.macro == :has_many
            records.each do |record|
              through.target.delete(through_record(record))
            end
          else
            records.each do |record|
              through.target = nil if through.target == through_record(record)
            end
          end
        end