from typing import Optional
from typing import List


def process_ip_headers(ip_header_raw: Optional[str] = None) -> List[str]:
    """
    Convert string to list of unique IPs.
    """
    if ip_header_raw is None:
        return []

    ip_headers = ip_header_raw.replace(" ", "").split(",")
    ip_headers = list(set(ip_headers))
    return ip_headers