def press(button, scope={})
      in_scope(scope) do
        begin
          click_button(button)
        rescue Capybara::ElementNotFound
          raise Kelp::MissingButton,
            "No button with value, id or text '#{button}' found"
        end
      end
    end
def press(button, scope={})
      in_scope(scope) do
        begin
          click_button(button)
        rescue Capybara::ElementNotFound
          raise Kelp::MissingButton,
            "No button with value, id or text '#{button}' found"
        end
      end
    end
Press a button on the page.

 @example
   press "Cancel"
   press "Submit", :within => "#survey"

 @param [String] button
   Capybara locator expression (id, name, or button text)
 @param [Hash] scope
   Scoping keywords as understood by {#in_scope}