public function testIsFunction()
{
// from js
$func = function () {
};
$this->assertFalse(__u::isFunction(array(1, 2, 3)), 'arrays are not functions');
$this->assertFalse(__u::isFunction('moe'), 'strings are not functions');
$this->assertTrue(__u::isFunction($func), 'but functions are');
// extra
$this->assertFalse(__u::isFunction('array_search'), 'strings with names of functions are not functions');
$this->assertFalse(__u::isFunction(new __u()));
$this->assertFalse(__u(array(1, 2, 3))->isFunction());
$this->assertFalse(__u('moe')->isFunction());
$this->assertTrue(__u($func)->isFunction());
$this->assertFalse(__u('array_search')->isFunction());
$this->assertFalse(__u(new __u())->isFunction());
// docs
$this->assertTrue(__u::isFunction(function () {
}));
$this->assertFalse(__u::isFunction('trim'));
}