ExecutorCompletionService

• https://dotnetcodr.com/2017/09/16/getting-the-result-of-the-first-completed-parallel-task-in-java/

• https://www.javacodemonk.com/use-executorcompletionservice-to-compute-results-from-5-different-datasources-in-parallel-28753553

• https://stackoverflow.com/questions/58510690/what-is-a-way-to-get-the-first-finish-future-from-a-list-of-future-in-java

• https://examples.javacodegeeks.com/core-java/util/concurrent/completionservice/java-completionservice-example/

take vs poll

• https://stackoverflow.com/questions/23379623/java-blockingqueue-take-vs-poll