public static ProgressEventDispatcher newRoot(
      EventHandlers eventHandlers, String description, long allocationUnits) {
    return newProgressEventDispatcher(
        eventHandlers, Allocation.newRoot(description, allocationUnits));
  }
Creates a new {@link ProgressEventDispatcher} with a root {@link Allocation}.

@param eventHandlers the {@link EventHandlers}
@param description user-facing description of what the allocation represents
@param allocationUnits number of allocation units
@return a new {@link ProgressEventDispatcher}
jib-core/src/main/java/com/google/cloud/tools/jib/builder/ProgressEventDispatcher.java