def get_feedback
      tokens = []

      begin
        setup_ssl(true)
      rescue SocketError => e
        puts "Error: #{e}"
        return tokens
      end

      if IO.select([@ssl], nil, nil, 1)
        while (line = @ssl.read(38))
          f = line.unpack('N1n1H64')
          time = Time.at(f[0])
          token = f[2].scan(/.{8}/).join(' ')
          tokens << token
        end
      end

      close_ssl

      return tokens
    end
def get_feedback
      tokens = []

      begin
        setup_ssl(true)
      rescue SocketError => e
        puts "Error: #{e}"
        return tokens
      end

      if IO.select([@ssl], nil, nil, 1)
        while (line = @ssl.read(38))
          f = line.unpack('N1n1H64')
          time = Time.at(f[0])
          token = f[2].scan(/.{8}/).join(' ')
          tokens << token
        end
      end

      close_ssl

      return tokens
    end
Calls the APNS feedback service and returns an array of expired push tokens
 @return [Array<String>] an array of expired push tokens