def get_latex_for_string(txt):
    """Convert to LaTeX form for the dummy back end.

    Parameters
    ----------
    txt : str
        The text component in LaTeX form (e.g. r'lpha^2'). It
        should not contain any non-LaTeX content.

    Returns
    -------
    latex : str
        The input text (i.e. no change).

    """
    return txt
