Reading across collections

[rofrankel]

📑 Proposed changes

Adopt AIP-159: Reading across collections

🍱 Types of changes

What types of changes does your code introduce to AEP? Put an x in the boxes that apply

• [ ] Enhancement
• [ ] New proposal
• [x] Migrated from google.aip.dev

📋 Your checklist for this pull request

Please review the AEP Style and Guidance for contributing to this repository.

General

• [x] Basic Guidance is met.
• [x] Ensure that your PR references AEPs correctly.

Additional checklist for a new AEP

• [ ] A new AEP should be no more than two pages if printed out.
• [ ] Ensure that the PR is editable by maintainers.
• [ ] Ensure that File structure guidelines are met.
• [ ] Ensure that Document structure guidelines are met.

💝 Thank you!