resize(int [], int newLen)

|-----------------+-------------------|
| expected return | param             |
|-----------------+-------------------|
| {1, 3}          | {1, 3, 5, 7}, 2   |
|-----------------+-------------------|
| {1, 2, 3, 0, 0} | {1, 2, 3}, 5      |
|-----------------+-------------------|
| null            | {0, 0, 0, 0}, 0   |
|-----------------+-------------------|
| null            | {1, 2, 3, 4}, -12 |
|-----------------+-------------------|