# File lib/mechanize/http/agent.rb, line 448 def request_add_headers request, headers = {} @request_headers.each do |k,v| request[k] = v end headers.each do |field, value| case field when :etag then request["ETag"] = value when :if_modified_since then request["If-Modified-Since"] = value when Symbol then raise ArgumentError, "unknown header symbol #{field}" else request[field] = value end end end