def get_users(self, full_name=None, email=None, username=None):
        """
        Send GET request to /users for users with optional full_name, email, and/or username filtering.
        :param full_name: str name of the user we are searching for
        :param email: str: optional email to filter by
        :param username: str: optional username to filter by
        :return: requests.Response containing the successful result
        """
        data = {}
        if full_name:
            data['full_name_contains'] = full_name
        if email:
            data['email'] = email
        if username:
            data['username'] = username
        return self._get_collection('/users', data)