code: void grab(KnowledgeHelper kh) {
          assert kh != null : "kh cannot be null";
          assert this.kh == null : "The previous user of this copier forgot to call release!";
          if (this.kh != null) {
              LOGGER.log(Level.WARNING, 
                      "The previous user of this copier forgot to call release. This causes a memory leak!");
          }
          this.kh = kh;
          this.uniqueIdProvider = 
                  new ProviderBasedUniqueIdFactory(new JBossRulesDerivedLocalUniqueIdValuesProvider(this.kh.getWorkingMemory(), 
                          this.propId));
      }
docs: Grabs this copier for use by a Drools consequence.
  
  @param workingMemory the consequence's {@link WorkingMemory}. Cannot
  be <code>null</code>.