Tests static methods.
public function testStaticMethods() {
// Test the RearrangeFilter::arrayKeyPlus method.
$original = array(
0 => 'one',
1 => 'two',
2 => 'three',
);
$expected = array(
1 => 'one',
2 => 'two',
3 => 'three',
);
$this
->assertSame(RearrangeFilter::arrayKeyPlus($original), $expected);
}