   #       query = 'SELECT * FROM Objects WHERE sha1 = $1'
   #       client.query query, [sha1], (err, result) ->
   #         console.log result.rows[0]
+  #         client.done()
   #
   # @api private
   # @see pg.Client

    @client (err, client) ->
      return callback err if err
      client.query args..., callback

  # Runs queries within a nested transaction, rolling back on any error.
  #

    @client (err, client) =>
      return callback err if err

      transaction = new Transaction client, @transaction, client.done
      transaction.start (err) =>
        return callback err if err

