# The identifier whose origin and scope is unknown (i.e. can not be deduced after effort).
#
# Instantiating this class asserts that a namespace can not be determined.
#
# @!attribute identifier 
#   @return [String]
#   The *verbatim* value of this identifier.
class Identifier::Unknown < Identifier

  validates_uniqueness_of :identifier

  protected

  def set_cached
    update_column(:cached, identifier)
  end 
end
