class Middleman::CallbackManager

def execute(keys, args=[], scope=self)
  callbacks = callbacks_for(keys)
  callbacks_count = callbacks.length + @subscribers.length
  return if callbacks_count < 1
  # ::Middleman::Util.instrument "callbacks.execute", keys: keys, length: callbacks_count do
  callbacks.each { |b| scope.instance_exec(*args, &b) }
  @subscribers.each { |b| scope.instance_exec(keys, args, &b) }
  # end
end