module HTTParty::ClassMethods

def uri_adapter(uri_adapter)

end
uri_adapter Addressable::URI
include HTTParty
class Foo

Allows setting a custom URI adapter. 
def uri_adapter(uri_adapter)
  raise ArgumentError, 'The URI adapter should respond to #parse' unless uri_adapter.respond_to?(:parse)
  default_options[:uri_adapter] = uri_adapter
end