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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_substitutions_from_config(config):
 """ Return a list of Substitution objects from the config, sorted alphabetically by pattern name. Returns an empty list if no Substitutions are specified. If there are problems parsing the values, a help message will be printed and an error will be thrown. """

    result = []
    pattern_names = config.options(SUBSTITUTION_SECTION)
    pattern_names.sort()
    for name in pattern_names:
        pattern_val = config.get(SUBSTITUTION_SECTION, name)
        list_rep = ast.literal_eval(pattern_val)
        substitution = parse_substitution_from_list(list_rep)
        result.append(substitution)
    return result