def filter_tokens(seq: List[Tuple[str, Tuple[int, int]]]) -> List[str]:
    """
    Filters out tokens based on specific criteria:
    1. Removes tokens that are only whitespace.
    2. Excludes tokens that are a single character in the original string.

    Args:
        seq: A list of tuples, where each tuple contains a token and its span (start, end) in the original string.

    Returns:
        A list of filtered tokens.
    """
    filtered_seq = [
        token
        for token, span in seq
        if len(token.strip()) > 0 and (span[1] - span[0] != 1)
    ]
    return filtered_seq

    Filters out tokens based on specific criteria:
    1. Removes tokens that are only whitespace.
    2. Excludes tokens that are a single character in the original string.

    Args:
        seq: A list of tuples, where each tuple contains a token and its span (start, end) in the original string.

    Returns:
        A list of filtered tokens.
    
src/openparse/tables/unitable/utils.py