class ActionDispatch::Routing::Mapper::Mapping

def verify_regexp_requirements(requirements, wildcard_options)
  requirements.each do |requirement, regex|
    next unless regex.is_a? Regexp
    if ANCHOR_CHARACTERS_REGEX.match?(regex.source)
      raise ArgumentError, "Regexp anchor characters are not allowed in routing requirements: #{requirement.inspect}"
    end
    if regex.multiline?
      next if wildcard_options.key?(requirement)
      raise ArgumentError, "Regexp multiline option is not allowed in routing requirements: #{regex.inspect}"
    end
  end
end