# File lib/selenium/webdriver/support/select.rb, line 105
        def deselect_by(how, what)
          case how
          when :text
            deselect_by_text what
          when :value
            deselect_by_value what
          when :index
            deselect_by_index what
          else
            raise ArgumentError, "can't deselect options by #{how.inspect}"
          end
        end