Add Cache.getAllPresent()

[BoD]

Description

Adds getAllPresent() with no argument to Cache, in addition to existing getAllPresent(keys: List<*>). In the original Guava library there was an asMap() method which could be used to get the contents of the cache.

Type of Change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Test Plan

Removed @Ignore from the getAllPresent() test.

Checklist:

Before submitting your PR, please review and check all of the following:

• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation (N/A)
• [x] My changes generate no new warnings
• [x] I have added tests that prove my change is effective
• [x] New and existing unit tests pass locally with my changes

Additional Notes:

Used clear() as an inspiration for the implementation.

[BoD]

Please document the default method, otherwise LGTM and I will be around to stamp. I see the other tickets - when do you need a release?

🙏 I've addressed the comments 👍

A release is not urgent, for now we've bundled the classes in the project - whenever you make a release, we'll use the dependency instead.