public void ChangeAproved_SwitchingTwice_SwitchesAproved()
        {
            var aprovedState = _audioClickFirst.Aproved;

            // first change
            _audioClickFirst.ChangeAproved();
            Assert.AreNotEqual(_audioClickFirst.Aproved, aprovedState,
                               "Failed ChangeAproved (first change): should not be "
                               + aprovedState);
            // second change
            _audioClickFirst.ChangeAproved();
            Assert.AreEqual(_audioClickFirst.Aproved, aprovedState,
                            "Failed ChangeAproved (second change): should be "
                            + aprovedState);
        }
        /// <summary>
        ///     Event handler processing mouse left button or touch screen
        ///     user actions
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void GridPointerReleased(object sender, PointerRoutedEventArgs e)
        {
            var point = e.GetCurrentPoint(this).Position;

            if (_isPointerPressedInTheMidle &&
                Math.Abs(point.X - _pointPointerPressedInTheMidle.X) < 1 &&
                Math.Abs(point.Y - _pointPointerPressedInTheMidle.Y) < 1)
            {
                // change Aproved property of click
                _audioClickBinded.ChangeAproved();
                SetBorderColour();
            }

            if (_isPointerPressedInTheRightArea &&
                Math.Abs(point.X - _pointPointerPressedInTheRightArea.X) < 1 &&
                Math.Abs(point.Y - _pointPointerPressedInTheRightArea.Y) < 1)
            {
                // expand marked damaged sample sequence to right
                _audioClickBinded.ExpandRight();
                ThresholdLevelDetected.Text = _audioClickBinded.ErrorLevelDetected.ToString("0.0");
                SetPolylines();
            }

            if (_isPointerPressedInTheLeftArea &&
                Math.Abs(point.X - _pointPointerPressedInTheLeftArea.X) < 1 &&
                Math.Abs(point.Y - _pointPointerPressedInTheLeftArea.Y) < 1)
            {
                // expand marked damaged sample sequence to right
                _audioClickBinded.ExpandLeft();
                ThresholdLevelDetected.Text = _audioClickBinded.ErrorLevelDetected.ToString("0.0");
                SetPolylines();
            }

            _isPointerPressedInTheMidle     = false;
            _isPointerPressedInTheRightArea = false;
            _isPointerPressedInTheLeftArea  = false;
        }