description: An optional list of hex-encoded SHA-256 hashes
                            of the authorized client certificates.
                          items:
                            type: string
                          type: array
                        verifyCertificateSpki:
                          description: An optional list of base64-encoded SHA-256

                          description: An optional list of hex-encoded SHA-256 hashes
                            of the authorized client certificates.
                          items:
                            type: string
                          type: array
                        verifyCertificateSpki:
                          description: An optional list of base64-encoded SHA-256

*   Added **categorical data** processing layers:
    *   `IntegerLookup` & `StringLookup`: build an index of categorical feature
        values
    *   `CategoryEncoding`: turn integer-encoded categories into one-hot,
        multi-hot, or tf-idf encoded representations
    *   `CategoryCrossing`: create new categorical features representing
        co-occurrences of previous categorical feature values