def find_users_by_email_starting_with(email_prefix=None, cursor=None, page_size=30):
    """
    Returns a command that retrieves users by its email_prefix, ordered by email.
    It returns a max number of users defined by page_size arg. Next result can be retrieved using cursor, in
    a next call. It is provided in cursor attribute from command.
    """
    email_prefix = email_prefix or ''

    return ModelSearchCommand(MainUser.query_email_starts_with(email_prefix),
                              page_size, cursor, cache_begin=None)
Returns a command that retrieves users by its email_prefix, ordered by email.
    It returns a max number of users defined by page_size arg. Next result can be retrieved using cursor, in
    a next call. It is provided in cursor attribute from command.