def batch_exists(keys, options = nil)
      policy = create_policy(options, BatchPolicy, default_batch_policy)
      results = Array.new(keys.length)

      if policy.use_batch_direct
        key_map = BatchItem.generate_map(keys)
        execute_batch_direct_commands(keys) do |node, batch|
          BatchDirectExistsCommand.new(node, batch, policy, key_map, results)
        end
      else
        execute_batch_index_commands(keys) do |node, batch|
          BatchIndexExistsCommand.new(node, batch, policy, results)
        end
      end

      results
    end
def batch_exists(keys, options = nil)
      policy = create_policy(options, BatchPolicy, default_batch_policy)
      results = Array.new(keys.length)

      if policy.use_batch_direct
        key_map = BatchItem.generate_map(keys)
        execute_batch_direct_commands(keys) do |node, batch|
          BatchDirectExistsCommand.new(node, batch, policy, key_map, results)
        end
      else
        execute_batch_index_commands(keys) do |node, batch|
          BatchIndexExistsCommand.new(node, batch, policy, results)
        end
      end

      results
    end
Check if multiple record keys exist in one batch call.
  The returned boolean array is in positional order with the original key array order.
  The policy can be used to specify timeouts and protocol type.