def led_partitions
      result, mutex = [], Mutex.new
      threads = cluster.partitions.map do |partition|
        Thread.new do
          Thread.abort_on_exception = true
          select = partition.leader == self
          mutex.synchronize { result << partition } if select
        end
      end
      threads.each(&:join)
      result
    end
def led_partitions
      result, mutex = [], Mutex.new
      threads = cluster.partitions.map do |partition|
        Thread.new do
          Thread.abort_on_exception = true
          select = partition.leader == self
          mutex.synchronize { result << partition } if select
        end
      end
      threads.each(&:join)
      result
    end
Returns a list of all partitions that are currently led by this broker.