public function concatExamples()
{
return ['alpha and numeric values' => [[['a', 'b', 'c'], [1, 2, 3]], ['a', 'b', 'c', 1, 2, 3]], 'variable arguments' => [[['a', 'b', 'c'], [1, 2, 3], [4, 5, 6]], ['a', 'b', 'c', 1, 2, 3, 4, 5, 6]], 'mixed arguments' => [[['a', 'b', 'c'], 1, [2, 3]], ['a', 'b', 'c', 1, 2, 3]]];
}