Initializes the auth settings for accessing MyAnimeList
    through its official API from a given username and password.
    :param username Your MyAnimeList account username.
    :param password Your MyAnimeList account password.
    :return A tuple containing your credentials.

def init_auth(username, password):
    """Initializes the auth settings for accessing MyAnimeList
    through its official API from a given username and password.
    :param username Your MyAnimeList account username.
    :param password Your MyAnimeList account password.
    :return A tuple containing your credentials.
    """
    username = username.strip()
    password = password.strip()
    credentials = (username, password)
    if helpers.verif_auth(credentials, header):
        return credentials
    else:
        raise ValueError(constants.INVALID_CREDENTIALS)