def use(conn = nil)
      conn_given = !!conn
      conn = conn_given ? conn : @pool.checkout
      begin
        yield Thread.current[:squirm_connection] = conn
      ensure
        Thread.current[:squirm_connection] = nil
        @pool.checkin conn unless conn_given
      end
    end
def use(conn = nil)
      conn_given = !!conn
      conn = conn_given ? conn : @pool.checkout
      begin
        yield Thread.current[:squirm_connection] = conn
      ensure
        Thread.current[:squirm_connection] = nil
        @pool.checkin conn unless conn_given
      end
    end
Uses a connection for all database access inside the given block. If no
 connection is given, then one will be checked out from the pool for use
 inside the block, and then checked back in when the method returns.