feat: Add list() method to all resource nouns

[vinnysenthil]

Colab for manual testing

Summary of Changes

• Added a _list_method property to AiPlatformResourceNoun to store GAPIC method name for each noun
• Added a create_time and update_time property to AiPlatformResourceNoun
• Added a single list() method that takes four optional fields and returns a list of SDK types
  • All of the fields except order_by are available in every GAPIC list methods
  • Added local sorting for GAPIC list methods that do not take order_by
• Added 3 unit tests to check correct GAPIC calls and local sorting
• Added aiplatform.init() to test class setup and dropped it from some unit tests

Fixes b/183498826 🦕

[sasha-gitg]

Strong preference to break down this conditional logic at the subclass level instead.

One option is to have two private list classes and pass in the filtering attributes.

class AiPlatformResourceNoun:
  def _list(..., 
                order_by: Optional[str],
                gapic_field_filter_name: Optional[str]:None,
                cls_field_filter_name: Optional[str]: None):
    ...
    cls_filter_schema = getattr(cls, cls_field_filter_schema, None) if cls_field_filter_name else set([])
    final_list = [
                self._construct_sdk_resource_from_gapic(
                    gapic_resource, credentials=creds
                )
                for gapic_resource in resource_list
                if gapic_field_filter_key and getattr(gapic_resource, gapic_field_filter_key)
                in cls_filter_schema
            ]
  def _list_with_local_order(...,order_by: Optional[str]):
     li = cls._list(..., order_by=None)
     # order here
     return li
     
  def list(...):
    return cls._list(...)
     
class _TrainingJob:
   def list(...):
      return cls._list_with_local_order(
        ...,
        order,
        gapic_field_filter_name='training_task_definition',
        cls_field_filter_name='_supported_training_schemas') # could just pass in the cls attribute as well

This will be more extensible in the future and allow external teams to use the list functionality without needing to change the base class.

[vinnysenthil]

Thanks for putting together this example! Adopting that option but will have the private _list method take a single cls_filter Callable that takes a gca_resource returns a bool that decides whether to include or exclude a given GAPIC object. Lmk if you have any concerns with that approach.

[sasha-gitg]

Why is the empty list needed here?

[vinnysenthil]

I ran into a few rare instances where the service returned a None instead of an empty list, this just serves as a fail safe against that.

[vinnysenthil]

@sasha-gitg I've made changes that reflect the structure you suggested, PTAL at the commit and lmk if it looks good. If so, I'll add doc strings to the private methods and a bit more test coverage 🙂

[sasha-gitg]

LGTM! Thanks for this one. I have one main question on ordering.