shadows/framework/src/main/java/org/robolectric/shadows/ShadowCaptioningManager.java
public void setFontScale(float fontScale) {
    this.fontScale = fontScale;

    for (CaptioningChangeListener captioningChangeListener : listeners) {
      captioningChangeListener.onFontScaleChanged(fontScale);
    }
  }
public void setFontScale(float fontScale) {
    this.fontScale = fontScale;

    for (CaptioningChangeListener captioningChangeListener : listeners) {
      captioningChangeListener.onFontScaleChanged(fontScale);
    }
  }
Sets the value to be returned by {@link CaptioningManager#getFontScale()}