@Override
public PCollection<T> apply(PCollection<T> in) {
WithKeys<IdT, T> withKeys = WithKeys.of(fn);
if (representativeType != null) {
withKeys = withKeys.withKeyType(representativeType);
}
return in.apply(withKeys)
.apply(
Combine.<IdT, T, T>perKey(
new Combine.BinaryCombineFn<T>() {
@Override
public T apply(T left, T right) {
return left;
}
}))
.apply(Values.<T>create());
}
