class UnsupportedVendor(Exception):
    """Unsupported vendor exception for VendorClient."""

    service: str
    vendor: str

    def __init__(self, service=None, vendor=None):
        if service is not None:
            self.service = service
        if vendor is not None:
            self.vendor = vendor

    def __str__(self):
        return f"Service {self.service} does not support vendor {self.vendor}."