shadows/framework/src/main/java/org/robolectric/shadows/ShadowDisplay.java
public void setFlags(int flags) {
    reflector(_Display_.class, realObject).setFlags(flags);

    if (!isJB()) {
      ShadowDisplayManager.changeDisplay(realObject.getDisplayId(),
          di -> di.flags = flags);
    }
  }
public void setFlags(int flags) {
    reflector(_Display_.class, realObject).setFlags(flags);

    if (!isJB()) {
      ShadowDisplayManager.changeDisplay(realObject.getDisplayId(),
          di -> di.flags = flags);
    }
  }
Changes the flags for this display.

Any registered {@link android.hardware.display.DisplayManager.DisplayListener}s will be
notified of the change.