byte[] labeledExpandHpke(byte[] prk, byte[] label, byte[] info, int nBytesToExpand/*L*/) {
        return labeledExpandForSuite(kdf, prk, hpkeSuiteId, label, info, nBytesToExpand);
    }
Section 5.1 Creating the Encryption Context:

HPKE implicit suite_id (this differs from the KEM suite id):

<pre>
suite_id = concat(
  "HPKE",
  I2OSP(kem_id, 2),
  I2OSP(kdf_id, 2),
  I2OSP(aead_id, 2)
)
</pre>
security-utils/src/main/java/com/yahoo/security/hpke/Hpke.java