private static boolean terminalType(Field f) {
        return f.getType().isPrimitive()
             || f.getType().isArray()
             || f.getType().getCanonicalName().startsWith("java.lang");
    }
Get a claim by name.

@param token token to retrieve claim from
@param claim the claim (field key)
@return string representation of claim
plugins/keycloak-oauth-policy/src/main/java/io/apiman/plugins/keycloak_oauth_policy/ClaimLookup.java