def set(value = true)
      assert_exists
      assert_enabled

      if (value && !set?) || (!value && set?)
        @object.click
      end
    end
def set(value = true)
      assert_exists
      assert_enabled

      if (value && !set?) || (!value && set?)
        @object.click
      end
    end
@api private


 Set the checkbox to the given value.

   checkbox.set?         #=> false
   checkbox.set
   checkbox.set?         #=> true
   checkbox.set(false)
   checkbox.set?         #=> false