def head(path, initheader = nil)
      res = request(Head.new(path, initheader))
      res.value unless @newimpl
      res
    end
def head(path, initheader = nil)
      res = request(Head.new(path, initheader))
      res.value unless @newimpl
      res
    end
Gets only the header from +path+ on the connected-to host.
 +header+ is a Hash like { 'Accept' => '*/*', ... }.

 This method returns a Net::HTTPResponse object.

 In version 1.1, this method might raise an exception for
 3xx (redirect). On the case you can get a HTTPResponse object
 by "anException.response".
 In version 1.2, this method never raises an exception.

     response = nil
     Net::HTTP.start('some.www.server', 80) {|http|
       response = http.head('/index.html')
     }
     p response['content-type']