class ActiveModel::Validations::NumericalityValidator

def prepare_value_for_validation(value, record, attr_name)
  return value if record_attribute_changed_in_place?(record, attr_name)
  came_from_user = :"#{attr_name}_came_from_user?"
  if record.respond_to?(came_from_user)
    if record.public_send(came_from_user)
      raw_value = record.public_send(:"#{attr_name}_before_type_cast")
    elsif record.respond_to?(:read_attribute)
      raw_value = record.read_attribute(attr_name)
    end
  else
    before_type_cast = :"#{attr_name}_before_type_cast"
    if record.respond_to?(before_type_cast)
      raw_value = record.public_send(before_type_cast)
    end
  end
  raw_value || value
end