def validate_section_names(section_names: List[str]):
    """Return section names that don't correspond to a defined enum."""
    if len(section_names) == 1 and section_names[0] == ALL_SECTIONS:
        return
    elif len(section_names) > 1 and ALL_SECTIONS in section_names:
        raise ValueError(f"{ALL_SECTIONS} may not be specified with other sections")

    invalid_names = [
        name for name in section_names if name not in section_string_to_enum
    ]
    if invalid_names:
        raise ValueError(f"The following section names are not valid: {invalid_names}")
    return
Return section names that don't correspond to a defined enum.
llama-index-integrations/readers/llama-index-readers-sec-filings/llama_index/readers/sec_filings/prepline_sec_filings/sections.py