code: public void restoreAllMockSecurityGroup(final Collection<MockSecurityGroup> securityGroups) {
          allMockSecurityGroup.clear();
          if (null != securityGroups) {
              for (MockSecurityGroup instance : securityGroups) {
                  allMockSecurityGroup.put(instance.getGroupId(), instance);
              }
          }
      }
docs: Clear {@link #allMockSecurityGroup} and restore it from given a collection of instances.
  
  @param securityGroups
  collection of MockSecurityGroup to restore