code: public void restoreAllMockVpc(final Collection<MockVpc> vpcs) {
          allMockVpcInstances.clear();
          if (null != vpcs) {
              for (MockVpc instance : vpcs) {
                  allMockVpcInstances.put(instance.getVpcId(), instance);
              }
          }
      }
docs: Clear {@link #allMockVpcInstances} and restore it from given a collection of instances.
  
  @param vpcs
  collection of Vpc to restore