class WWW::Mechanize

def set_proxy(addr, port, user = nil, pass = nil)

+addr+ should be a host, with no "http://"
Sets the proxy address, port, user, and password 
def set_proxy(addr, port, user = nil, pass = nil)
  @proxy_addr, @proxy_port, @proxy_user, @proxy_pass = addr, port, user, pass
end