private static Integer resolveTid(String idcXref, int srcId, FinDate asOf) {
    IDCDataSource source = IDCDataSourcesLoader.getIDCDataSource(srcId);
    if (source == null)
        return null;
    if (source.xrefProviderId == RefProviderType.IDC_MARKET.getId()) {
        String fullXref = idcXref + "." + source.source;
        XRefCache cache = XRefCache.getInstance(XRefType.INSTRUMENT, RefProviderType.IDC_MARKET, null);
        return cache.getId(fullXref, asOf, true);
    }
    else {
        XRefCache cache = XRefCache.getInstance(XRefType.INSTRUMENT, RefProviderType.getInstance(source.xrefProviderId), null);
        return cache.getId(idcXref, asOf, false);
    }
    }