in src/main/java/com/gerritforge/gerrit/plugins/account/GerritAccountRemover.java [108:120]
private void removeExternalIds(AccountApi account) throws RestApiException {
List<String> externalIds =
account.getExternalIds().stream()
.map(eid -> eid.identity)
.filter(eid -> !eid.startsWith(ExternalId.SCHEME_USERNAME))
.filter(eid -> !eid.startsWith(ExternalId.SCHEME_UUID))
.filter(eid -> !eid.startsWith(ExternalId.SCHEME_GERRIT))
.filter(Objects::nonNull)
.collect(Collectors.toList());
if (externalIds.size() > 0) {
account.deleteExternalIds(externalIds);
}
}