e</li>
<li><code>lowerValue</code> : The value corresponding to the left thumb current position</li>
<li><code>upperValue</code> : The value corresponding to the right thumb current position</li>
<li><code>stepValue</code> : If set, will snap to discrete step points along the slider . Default to nil.</li>
<li><code>trackTintColor</code> : The track color</li>
<li><code>trackHighlightTintColor</code> : The color of the section of the track located between the two thumbs</li>
<li><code>thumbTintColor</code>: 