class DRb::DRbObject

def initialize(obj, uri=nil)

will be a stub for.
this is +nil+. +uri+ is the URI of the remote object that this
+obj+ is the (local) object we want to create a stub for. Normally

Create a new remote object stub. 
def initialize(obj, uri=nil)
  @uri = nil
  @ref = nil
  case obj
  when Object
    is_nil = obj.nil?
  when BasicObject
    is_nil = false
  end
  if is_nil
    return if uri.nil?
    @uri, option = DRbProtocol.uri_option(uri, DRb.config)
    @ref = DRbURIOption.new(option) unless option.nil?
  else
    @uri = uri ? uri : (DRb.uri rescue nil)
    @ref = obj ? DRb.to_id(obj) : nil
  end
end