Largest XOR sum subarray

You are given a sequence $A$ of $N$ numbers. Pick one contiguous subarray of it. The XOR sum of a subarray is the value you get by XOR-ing every element in that subarray.

Given $A$, write a program that finds the largest XOR sum over all contiguous subarrays of length at least 1.

The first line contains the number of test cases $T$. ($1 \le T \le 10$)

Each test case takes two lines. The first line contains the size of the sequence $N$ ($1 \le N \le 100\,000$), and the second line contains the $N$ elements of $A$ separated by spaces. Each element is a non-negative integer that fits in a 32-bit signed integer, so it is an integer between $0$ and $2^{31}-1$.

For each test case, print the largest XOR sum over the contiguous subarrays of $A$ on its own line.