class Redis::Cluster

def send_command(command, &block)
  cmd = command.first.to_s.downcase
  case cmd
  when 'acl', 'auth', 'bgrewriteaof', 'bgsave', 'quit', 'save'
    @node.call_all(command, &block).first
  when 'flushall', 'flushdb'
    @node.call_master(command, &block).first
  when 'wait'     then @node.call_master(command, &block).reduce(:+)
  when 'keys'     then @node.call_slave(command, &block).flatten.sort
  when 'dbsize'   then @node.call_slave(command, &block).reduce(:+)
  when 'lastsave' then @node.call_all(command, &block).sort
  when 'role'     then @node.call_all(command, &block)
  when 'config'   then send_config_command(command, &block)
  when 'client'   then send_client_command(command, &block)
  when 'cluster'  then send_cluster_command(command, &block)
  when 'readonly', 'readwrite', 'shutdown'
    raise OrchestrationCommandNotSupported, cmd
  when 'memory'   then send_memory_command(command, &block)
  when 'script'   then send_script_command(command, &block)
  when 'pubsub'   then send_pubsub_command(command, &block)
  when 'discard', 'exec', 'multi', 'unwatch'
    raise AmbiguousNodeError, cmd
  else
    node = assign_node(command)
    try_send(node, :call, command, &block)
  end
end