def unsupplied_replacement(variable, default_variable, verbose, variable_str):
    """ If a given variable has the letters "unsupplied" in it
        then return the given default variable.
    """
    replacement = variable
    if 'unsupplied' in variable:
        replacement = default_variable
        if verbose >= 4:
            print(' '.join([variable_str, 'was unsupplied. Changed to use ',
                default_variable]))
    return replacement
