module DRb::DRbProtocol

URI, but an error occurs in opening it, a DRbConnError is raised.
URI, then a DRbBadURI error is raised. If a protocol accepts the
URI by raising a DRbBadScheme error. If no protocol recognises the
try to open the URI. Each protocol signals that it does not handle that
The DRbProtocol module asks each registered protocol in turn to

Open a client connection to +uri+ with the configuration +config+.

def open(uri, config, first=true)
  @protocol.each do |prot|
    begin
      return prot.open(uri, config)
    rescue DRbBadScheme
    rescue DRbConnError
      raise($!)
    rescue
      raise(DRbConnError, "#{uri} - #{$!.inspect}")
    end
  end
  if first && (config[:auto_load] != false)
    auto_load(uri)
    return open(uri, config, false)
  end
  raise DRbBadURI, 'can\'t parse uri:' + uri
end