Added more documentation to isEnabled() and resolves
/**
* Determine whether or not this element is selected or not. This operation only applies to input
* elements such as checkboxes, options in a select and radio buttons.
+ * For more information on which elements this method supports,
+ * refer to the <a href="https://w3c.github.io/webdriver/webdriver-spec.html#is-element-selected">specification</a>.
*
* @return True if the element is currently selected or checked, false otherwise.
*/
