k-nearest alg：如何手动设置K？

i want to predict a unlabeled item from K-NEAREST neighbour alg. but in default K=1 from package machine learning readthedocs

how can I set K manually???

<?php
$samples = [[1, 3], [1, 4], [2, 4], [3, 1], [4, 1], [4, 2]];
$labels = ['yes', 'yes', 'no', 'yes', 'no', 'no'];
$class = new KNearestNeighbors();
$class->train($samples, $labels);
$class->predict(1,7);
?>

As you may further read in the documentation, you may define K as following:

$class = new KNearestNeighbors($k=4);

Note that the default value of K is 3.