presto-main/src/main/java/io/prestosql/execution/scheduler/UniformNodeSelector.java/UniformNodeSelector/selectRandomNodes
class UniformNodeSelector:    @Override
    public List<InternalNode> selectRandomNodes(int limit, Set<InternalNode> excludedNodes)
    {
        return selectNodes(limit, randomizedNodes(nodeMap.get().get(), includeCoordinator, excludedNodes));
    }