find_with_ids

# File activerecord/lib/active_record/relation/finder_methods.rb, line 411
    def find_with_ids(*ids)
      raise UnknownPrimaryKey.new(@klass) if primary_key.nil?

      expects_array = ids.first.kind_of?(Array)
      return ids.first if expects_array && ids.first.empty?

      ids = ids.flatten.compact.uniq

      case ids.size
      when 0
        raise RecordNotFound, "Couldn't find #{@klass.name} without an ID"
      when 1
        result = find_one(ids.first)
        expects_array ? [ result ] : result
      else
        find_some(ids)
      end
    rescue RangeError
      raise RecordNotFound, "Couldn't find #{@klass.name} with an out of range ID"
    end