code: private void obtainNumberOfDigits(@NonNull final TypedArray typedArray) {
          int defaultValue = getContext().getResources()
                  .getInteger(R.integer.digit_picker_preference_default_number_of_digits);
          setNumberOfDigits(typedArray
                  .getInteger(R.styleable.DigitPickerPreference_numberOfDigits, defaultValue));
      }
docs: Obtains the number of digits of the numbers, the preference allows to choose, from a specific
  typed array.
  
  @param typedArray
  The typed array, the number of digits should be obtained from, as an instance of the
  class {@link TypedArray}. The typed array may not be null