jodd-bean/src/main/java/jodd/typeconverter/Converter.java
public BigInteger toBigInteger(final Object value, final BigInteger defaultValue) {
		final BigInteger result = toBigInteger(value);
		if (result == null) {
			return defaultValue;
		}
		return result;
	}
public BigInteger toBigInteger(final Object value, final BigInteger defaultValue) {
		final BigInteger result = toBigInteger(value);
		if (result == null) {
			return defaultValue;
		}
		return result;
	}
Converts value to <code>BigInteger</code>. Returns default value
when conversion result is <code>null</code>