shadows/framework/src/main/java/org/robolectric/shadows/ShadowMediaPlayer.java
@Implementation
  protected void start() {
    if (checkStateError("start()", startableStates)) {
      if (state == PLAYBACK_COMPLETED) {
        startOffset = 0;
      }
      state = STARTED;
      doStart();
    }
  }
@Implementation
  protected void start() {
    if (checkStateError("start()", startableStates)) {
      if (state == PLAYBACK_COMPLETED) {
        startOffset = 0;
      }
      state = STARTED;
      doStart();
    }
  }
Simulates private native method {@link MediaPlayer#_start()}. Sets state to STARTED and calls
{@link #doStart()} to start scheduling playback callback events.

<p>If the current state is PLAYBACK_COMPLETED, the current position is reset to zero before
starting playback.

@see #doStart()