protected Map<String, String> getPrefixedProperties(String prefix) {
        Map<String, String> rval = new HashMap<>();
        Iterator<String> keys = getConfig().getKeys();
        while (keys.hasNext()) {
            String key = keys.next();
            if (key.startsWith(prefix)) {
                String[] value = getConfig().getStringArray(key);
                key = key.substring(prefix.length());
                if (value.length == 0) {
                    rval.put(key, null);
                } else if (value.length == 1) {
                    rval.put(key, value[0]);
                } else {
                    rval.put(key, String.join(",", value));
                }
            }
        }
        return rval;
    }
Gets a map of properties prefixed by the given string.
manager/api/core/src/main/java/io/apiman/manager/api/core/config/ApiManagerConfig.java