.
We can also add the following test cases
```
TEST(LookupAffiliationResponseParserTest, IgnoreDuplicateEquivalenceClasses) {
std::vector<FacetURI> requested_facet_uris = {
FacetURI::FromCanonicalSpec("https://example.com")};
affiliation_pb::LookupAffiliationByHashPrefixResponse response;
auto* affiliation1 = response.add_affiliations();
affiliation1->add_facet()->set_id("https://example.com");
affiliation1->add_facet()->set_id("https://example2.com");
// Duplicate equivalence class in the same response.
auto* affiliation2 = response.add_affiliations();
affiliation2->add_facet()->set_id("https://example.com");
affiliation2->add_facet()->set_id("https://example2.com");
AffiliationFetcherInterface::ParsedFetchResponse result;
EXPECT_TRUE(ParseLookupAffiliationResponse(requested_facet_uris, response, &result));
EXPECT_EQ(1u, result.affiliations.size());
}
TEST(LookupAffiliationResponseParserTest, IgnoreUnrequestedEquivalenceClasses) {
std::vector<FacetURI> requested_facet_uris = {
FacetURI::FromCanonicalSpec("https://example.com")}; affiliation_pb::LookupAffiliationByHashPrefixResponse response;
auto* affiliation = response.add_affiliations();
affiliation->add_facet()->set_id("https://unrequested.example.com");
affiliation->add_facet()->set_id("https://unrequested2.example.com");
AffiliationFetcherInterface::ParsedFetchResponse result;
EXPECT_TRUE(ParseLookupAffiliationResponse(requested_facet_uris, response, &result));
EXPECT_TRUE(result.affiliations.empty());
}
```