private ValuesByUnderlying InitializeIntLookup()
{
var vals = new IntIntMap(values.Count + 1, 0.55f);
for (int i = 0; i < values.Count; ++i)
{
var value = values[i].IntValue();
if (vals.Get(value) == IntIntMap.NoValue)
{
vals.Put(value, i);
}
}
return(new ValuesByUnderlying {
IntMap = vals
});
}