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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_scheme_dirs():
 """Return a set of all scheme directories."""

    scheme_glob = rel_to_cwd('schemes', '**', '*.yaml')
    scheme_groups = glob(scheme_glob)
    scheme_groups = [get_parent_dir(path) for path in scheme_groups]
    return set(scheme_groups)