code: public void add(WorkbenchEntry entry) {
  		assert ! entry.isEmpty() : entry;
  		assert ! entry.acquired : entry;
  		entries.add(entry);
  		approximatedSize.incrementAndGet();
  	}
docs: Adds a nonempty, not acquired workbench entry to the workbench.
  
  @param entry a nonempty, not acquired workbench entry.