def of_kind?(attribute, message = :invalid)
      attribute, message = normalize_arguments(attribute, message)

      if message.is_a? Symbol
        !where(attribute, message).empty?
      else
        messages_for(attribute).include?(message)
      end
    end
def of_kind?(attribute, message = :invalid)
      attribute, message = normalize_arguments(attribute, message)

      if message.is_a? Symbol
        !where(attribute, message).empty?
      else
        messages_for(attribute).include?(message)
      end
    end
Returns +true+ if an error on the attribute with the given message is
 present, or +false+ otherwise. +message+ is treated the same as for +add+.

   person.errors.add :age
   person.errors.add :name, :too_long, { count: 25 }
   person.errors.of_kind? :age                                            # => true
   person.errors.of_kind? :name                                           # => false
   person.errors.of_kind? :name, :too_long                                # => true
   person.errors.of_kind? :name, "is too long (maximum is 25 characters)" # => true
   person.errors.of_kind? :name, :not_too_long                            # => false
   person.errors.of_kind? :name, "is too long"                            # => false