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