public void registerContainerPlacementAction(ContainerPlacementRequestMessage requestMessage) {
    containerManager.registerContainerPlacementAction(requestMessage, containerAllocator);
  }
Registers a ContainerPlacement action, this method is invoked by ContainerPlacementRequestAllocator. {@link ContainerProcessManager}
needs to intercept container placement actions between ContainerPlacementRequestAllocator and {@link ContainerManager} to avoid
cyclic dependency between {@link ContainerManager} and {@link ContainerAllocator} on each other

@param requestMessage request containing details of the desited container placement action
samza-core/src/main/java/org/apache/samza/clustermanager/ContainerProcessManager.java