Java factorial tail-call elimination

Factorial.java

import java.math.BigInteger;
import static java.math.BigInteger.ONE;

// Factorial care of functional Programming in Java - Venkat Subramaniam
class Factorial {
    static TailCall<BigInteger> factorial(long n) {
        return factorialRec(ONE, BigInteger.valueOf(n));
    }
    static TailCall<BigInteger> factorialRec(BigInteger factorial, BigInteger number) {
        if(number.equals(ONE)) {
            return TailCalls.done(factorial);
        } else {
            return TailCalls.call(() -> factorialRec(factorial.multiply(number), number.subtract(ONE)));
        }
    }

    public static void main(String[] args) {
        System.out.println(factorial(100).invoke());
        // Outputs 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000
        // Verify here: http://www.wolframalpha.com/input/?i=factorial+100
    }
}

@FunctionalInterface
interface TailCall<T> {
    TailCall<T> apply();
    default boolean isComplete() { return false; }
    default T result() { throw new Error("not implemented"); }
    default T invoke() { return Stream.iterate(this, TailCall::apply).filter(TailCall::isComplete).findFirst().get().result();}
}

class TailCalls {
    static <T> TailCall<T> call(TailCall<T> nextCall) {
        return nextCall;
    }

    static <T> TailCall<T> done(T value) {
        return new TailCall<T>() {
            public boolean isComplete() { return true; }
            public T result() { return value; }
            public TailCall<T> apply() { throw new Error("Not implemented");}
        };
    }
}