ng build error - Property 'requestMIDIAccess' does not exist
<p>I am trying to build an Angular2 project, using the Web Midi API. </p>

<p>When running<code>ng build</code>, I am not able to complete the process due to certain errors thrown, specifically:</p>

<pre>
Error in bail mode: [default] /Users/JmsToh/GitHub/web-editor/web-editor/src/app/midi.service.ts:43:22 
Property 'requestMIDIAccess' does not exist on type 'Navigator'.
</pre>

<p>This comes from this part of the code:</p>

<pre><code>if (navigator.requestMIDIAccess) {
  this.browserMidiCompatible = true;
  navigator.requestMIDIAccess({ sysex: false })
    .then(this.onMIDISuccess.bind(this), this.onMIDIReject.bind(this));
} else {
  alert("Platform not compatible");
}
</code></pre>

<p>The app runs fine on Chrome when running <code>ng serve</code>.Is there any way to get Angular2 to ignore the error when building?</p>