public function testExists()
{
$snippet = $this->snippetFromMethod(Sink::class, 'exists');
$snippet->addLocal('sink', $this->sink);
$this->connection->getSink(Argument::any())->shouldBeCalled()->willReturn([]);
$this->sink->setConnection($this->connection->reveal());
$res = $snippet->invoke();
$this->assertEquals('Sink exists!', $res->output());
}