def METHOD_NAME() -> None:
    n = NamingConvention()
    assert n.normalize_identifier("camelCase") == "camelCase"
    assert n.normalize_identifier("_camelCase") == "_camelCase"
    assert n.normalize_identifier("_snake_case") == "_snake_case"
    assert n.normalize_identifier("_snake_case_") == "_snake_casex"
    assert n.normalize_identifier("Snake---🛑case_") == "snake_casex"
    assert n.normalize_identifier("--🛑Snake---🛑case_") == "___Snake_casex"
    # dashes are compacted
    assert n.normalize_identifier("Snake-______c__ase_") == "snake_c_asex"
    assert n.normalize_identifier("Snake-______c__ase_") == "snake_c_asex"
    # but not the leading
    assert n.normalize_identifier("-______Snake-______c__ase_") == "_______Snake_c_asex"
    # starting digit
    assert n.normalize_identifier("281782918739821") == "p_281782918739821"