verify_regexp_requirement

# File actionpack/lib/action_dispatch/routing/mapper.rb, line 206
          def verify_regexp_requirement(requirement)
            if requirement.source =~ ANCHOR_CHARACTERS_REGEX
              raise ArgumentError, "Regexp anchor characters are not allowed in routing requirements: #{requirement.inspect}"
            end

            if requirement.multiline?
              raise ArgumentError, "Regexp multiline option is not allowed in routing requirements: #{requirement.inspect}"
            end
          end