::getCreatedTime() sometimes returns null instead of integer

Problem/Motivation

In WorkspaceInterface, UserInterface, NodeInterface, and CommentInterface, ::getCreatedTime() is defined as returning int. However, sometimes implementations will return null; see 🐛 getCreatedTime returns string instead of integer Needs work .

Proposed resolution

Ensure it cannot return null or update the interfaces.

Remaining tasks

Decide what to do. Implement.

User interface changes

None.

Introduced terminology

None.

API changes

Interfaces may allow null return values for ::getCreatedTime().

Data model changes

None.

Release notes snippet