static byte[] labeledExpandForSuite(Kdf kdf, byte[] prk, byte[] suiteId, byte[] label, byte[] info, int nBytesToExpand/*L*/) {
        byte[] labeledInfo = concat(i2osp2((short)nBytesToExpand), HPKE_V1_LABEL, suiteId, label, info);
        return kdf.expand(prk, labeledInfo, nBytesToExpand);
    }
Section 4 Cryptographic Dependencies:

<pre>
def LabeledExpand(prk, label, info, L):
  labeled_info = concat(I2OSP(L, 2), "HPKE-v1", suite_id,
                        label, info)
  return Expand(prk, labeled_info, L)
</pre>

We take in the KDF and suite ID explicitly, to allow method reuse between KEM and HPKE.
security-utils/src/main/java/com/yahoo/security/hpke/LabeledKdfUtils.java