protected final Optional<SamzaResourceRequest> peekReadyPendingRequest() {
    SamzaResourceRequest pendingRequest = resourceRequestState.peekPendingRequest();
    return Optional.ofNullable(pendingRequest);
  }
Retrieves, but does not remove, the next pending request in the queue with the {@link SamzaResourceRequest#getRequestTimestamp()}
that is greater than the current timestamp.

@return  the pending request or {@code null} if there is no pending request.
samza-core/src/main/java/org/apache/samza/clustermanager/ContainerAllocator.java