// collect the indices
internal void collectIndices(ImmutableSet.Builder <Index> builder)
{
Index.ifPresent(idx => builder.add(idx));
IndexInterpolated.ifPresent(idx => builder.add(idx));
}
// collect the currencies
internal void collectCurrencies(ImmutableSet.Builder <Currency> builder)
{
KnownAmount.ifPresent(amt => builder.add(amt.Currency));
Index.ifPresent(idx => builder.add(idx.Currency));
IndexInterpolated.ifPresent(idx => builder.add(idx.Currency));
}
