title: How to find proper harness by id?
body: <p>In my component tests, I need to find a proper Input element.</p>
  <p>I can find all of them by doing:</p>
  <pre><code>let loader: HarnessLoader = TestbedHarnessEnvironment.loader(fixture);
  const inputs = await loader.getAllHarnesses(MatInputHarness);
  expect(inputs).toBeTruthy();
  </code></pre>
  <p>But how can I find a proper input in the array?</p>
  <p>Deep inside, each 'input' has the id because I see it:</p>
  <pre><code>console.log(`id: ${await inputs[0].getId()}`);
  </code></pre>
  <p>outputs the proper id.</p>
  <p>Do I have to go in a loop through the whole list of inputs to check the id of every element? And call 'await' for each of those?</p>
  <p>I'm afraid this might be too computational-heavy. Also, this just smells wrong.</p>
  <p>How do I get a required input element by id?</p>
  <p>Thanks!</p>