code: public PatchingResult rollbackLast(final ContentVerificationPolicy contentPolicy, final boolean resetConfiguration, InstallationManager.InstallationModification modification) throws PatchingException {
  
          // Determine the patch id to rollback
          String patchId;
          final List<String> oneOffs = modification.getPatchIDs();
          if (oneOffs.isEmpty()) {
              patchId = modification.getCumulativePatchID();
              if (patchId == null || Constants.NOT_PATCHED.equals(patchId)) {
                  throw PatchLogger.ROOT_LOGGER.noPatchesApplied();
              }
          } else {
              patchId = oneOffs.get(0);//oneOffs.get(oneOffs.size() - 1);
          }
          return rollbackPatch(patchId, contentPolicy, false, resetConfiguration, modification);
      }
docs: Rollback the last applied patch.
  
  @param contentPolicy      the content policy
  @param resetConfiguration whether to reset the configuration
  @param modification       the installation modification
  @return the patching result
  @throws PatchingException