I tried out the 'Query Account' API to get the account IDs of the users by inputting the usernames. A simple example is:
https://gerrit.wikimedia.org/r/accounts/?q=rammanojpotla&q=some_random_username
The above query only returns the accountID user with username: "some_random_user" but ignores the first query. I performed the same request with the following API
https://gerrit.wikimedia.org/r/changes/?q=owner:rammanojpotla&q=owner:some_random_user
The above query returns the results regarding the two users. But This is not the case with the initial query!!
url to the doc: https://gerrit-review.googlesource.com/Documentation/rest-api-accounts.html#query-account