archaius-core/src/main/java/com/netflix/config/ConfigurationWithPollingSource.java
@Override
    public BigInteger getBigInteger(String key, BigInteger defaultValue) {
        return config.getBigInteger(key, defaultValue);
    }
@Override
    public BigInteger getBigInteger(String key, BigInteger defaultValue) {
        return config.getBigInteger(key, defaultValue);
    }
Delegates to the underlying configuration.