code: public List<User> findUsers(String emailOrUsername) throws GitLabApiException {
          return (findUsers(emailOrUsername, getDefaultPerPage()).all());
      }
docs: Search users by Email or username
  
  <pre><code>GitLab Endpoint: GET /users?search=:email_or_username</code></pre>
  
  @param emailOrUsername the email or username to search for
  @return the User List with the email or username like emailOrUsername
  @throws GitLabApiException if any exception occurs