Saving of Public and Private Key to a file

How can I save the generated public and private key to a file and also load them from that file and also, how do I serialize and deserialize in OpenFHE-Python.

Please see the examples ending with “-serial.py” in openfhe-python/examples/pke at main · openfheorg/openfhe-python · GitHub There are examples there for BGV,. BFV and CKKS.