krb5_set_principal_realm
ret = krb5_set_principal_realm(context, princ, realm);
code = krb5_set_principal_realm(ctx, mcreds.server, realm);
ret = krb5_set_principal_realm(context, srvcp, fbrealms[0]);
retval = krb5_set_principal_realm(ctx, princ, realm);
krb5_set_principal_realm,