presto-main/src/main/java/io/prestosql/execution/TaskManagerConfig.java/TaskManagerConfig/getInitialSplitsPerNode
class TaskManagerConfig:    @Min(1)
    public int getInitialSplitsPerNode()
    {
        if (initialSplitsPerNode == null) {
            return maxWorkerThreads;
        }
        return initialSplitsPerNode;
    }