Hamcrest matching an object array containing a property with a substring value

Question

I am wanting to Phockito (PHP version of Mockito) mock a specific journey with my function that takes an array as an argument...

How would I use Hamcrest matchers to specify just one of the properties of said array?

The function in question looks like this:

function getStuff($path) {
  $arr = [
    'requestUri' => self::BASE_URI . $path,
    ...
  ];

  return doMoreStuff($arr);
}

I am wanting to specify a Phockito route for a doMoreStuff mock that uses a specific path within the requestUri property.

I have looked at using arrayContaining:

Phockito($myMock)->doMoreStuff(
    arrayContaining(['requestUri' => containsString('some-path')])
)->returns('some value);

but this doesn't seem to work..