0. Make sure you don't have Unity installed in ../Applications/Unity/Unity.app
1. Run 5.4.0a5 DA.
2. Proceed to Components stage.
3. Select Documentation, Web Player, Standard Assets and Example project components.
4. Press Continue. Select Destination and press Continue.

Actual result: You'll get message "Can't install the selected components on this disk. You tried to install items that require Unity 5.4.0a5, but Unity is not installed on the disk you chose. Please either add Unity to your selection or deselect the components which require Unity." and won't be able to install these components.
Expected result: Actually these behaviour is partially correct.
1. Documentation, Standard Assets and Web player require Unity installed, so need to be marked with asterisks.
2. Although, Example project is not related to ../Applications/Unity/Unity.app and is installed to /Users/Shared/Unity, so don't require Unity and must be installed whenever Unity is installed or not.