public UpdateItemSpec withExpected(Collection<Expected> expected) {
if (expected == null) {
this.expected = null;
return this;
}
Set<String> names = new LinkedHashSet<String>();
for (Expected e : expected) names.add(e.getAttribute());
if (names.size() != expected.size()) {
throw new IllegalArgumentException(
"attribute names must not duplicate in the list of expected");
}
this.expected = Collections.unmodifiableCollection(expected);
return this;
}
