# File lib/redis.rb, line 1110
  def sadd(key, member)
    synchronize do |client|
      client.call [:sadd, key, member] do |reply|
        if member.is_a? Array
          # Variadic: return integer
          reply
        else
          # Single argument: return boolean
          _boolify.call(reply)
        end
      end
    end
  end