code: function mkZAddress(a_pk, pk_enc, zcPaymentAddressHash) {
    zcPaymentAddressHash = zcPaymentAddressHash || zconfig.mainnet.zcPaymentAddressHash;
  
    const buf = Buffer.from(zcPaymentAddressHash + a_pk + pk_enc, 'hex');
    return bs58check.encode(buf).toString('hex');
  }
docs: /*
  Makes a Z address given:
  @param {String} a_pk (paying key)
  @param {String} pk_enc key (transmission key)
  @param {String} zcPaymentAddressHash (hash for payment address, optional)
  @return {String} Zaddress