You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sharding_session_proxy.rb
    path of file: ./repos/sunspot/sunspot/lib/sunspot/session_proxy
    
    the code of the file until where you have to start completion: require File.join(File.dirname(__F
    
      def remove_all(clazz = nil)
        if clazz
          raise NotSupportedError, "Sharding session proxy does not support remove_all with an argument."
        else
          all_sessions.each { |session| session.remove_all }
        end
      end