URI::Generic#check_opaque

# File tmp/rubies/ruby-4.1.0-preview1/lib/uri/generic.rb, line 876
def check_opaque(v)
  return v unless v

  # raise if both hier and opaque are not nil, because:
  # absoluteURI   = scheme ":" ( hier_part | opaque_part )
  # hier_part     = ( net_path | abs_path ) [ "?" query ]
  if @host || @port || @user || @path  # userinfo = @user + ':' + @password
    raise InvalidURIError,
      "cannot set opaque with host, port, userinfo or path"
  elsif v && parser.regexp[:OPAQUE] !~ v
    raise InvalidComponentError,
      "bad component(expected opaque component): #{v}"
  end

  return true
end