code: protected final <T extends AItemSpecifics<?,  ?>> int findFirstIdxFor(final List<T> pOutdGdSpList, final IHasIdLongVersionName pItem) {
      int j = 0;
      while (!pOutdGdSpList.get(j).getItem().getItsId().equals(pItem.getItsId())) {
        j++;
      }
      return j;
    }
docs: <p>Find the first index of specific with given item.</p>
  @param <T> item specifics type
  @param pOutdGdSpList GS list
  @param pItem Goods
  @return the first index of specific with given item
  it throws Exception - if out of bounds