public void setPhase(double phase) {
    if ((phase < 0) || (phase > 1)) {
      throw new IllegalArgumentException("phase: " + phase);
    }

    mPhase = phase;
    invalidate();
  }
Sets the phase of this indicator.

@param phase phase {@code [0, 1]}: {@code 1} when the maximum amount of time is remaining,
    {@code 0} when no time is remaining.
java/com/google/android/apps/authenticator/CountdownIndicator.java