code: @Override
    public final PurchaseReturnLine process(
      final Map<String, Object> pAddParam,
        final PurchaseReturnLine pEntityPb,
          final IRequestData pRequestData) throws Exception {
      PurchaseReturnLine entity = this.prcAccEntityPbCopy
        .process(pAddParam, pEntityPb, pRequestData);
      if (entity.getReversedId() != null) {
        throw new ExceptionWithCode(ExceptionWithCode.FORBIDDEN,
          "attempt_to_reverse_reversed");
      }
      entity.setReversedId(pEntityPb.getItsId());
      entity.setItsQuantity(entity.getItsQuantity().negate());
      entity.setSubtotal(entity.getSubtotal().negate());
      entity.setTotalTaxes(entity.getTotalTaxes().negate());
      entity.setItsTotal(entity.getItsTotal().negate());
      entity.setForeignSubtotal(entity.getForeignSubtotal().negate());
      entity.setForeignTotal(entity.getForeignTotal().negate());
      entity.setForeignTotalTaxes(entity.getForeignTotalTaxes().negate());
      return entity;
    }
docs: <p>Process entity request.</p>
  @param pAddParam additional param, e.g. return this line's
  document in "nextEntity" for farther process
  @param pRequestData Request Data
  @param pEntity Entity to process
  @return Entity processed for farther process or null
  @throws Exception - an exception