code: def test_validate(self):
      kwargs = {
          "id": "def456",
          "created": datetime.datetime.utcnow(),
      }
  
      checkpoint = Checkpoint(path=123, **kwargs)
      assert checkpoint.validate() == ["path must be a string"]
  
      checkpoint = Checkpoint(step="lol", **kwargs)
      assert checkpoint.validate() == ["step must be an integer"]
  
      checkpoint = Checkpoint(metrics="lol", **kwargs)
      assert checkpoint.validate() == ["metrics must be a dictionary"]
  
      checkpoint = Checkpoint(metrics={"foo": Blah()}, **kwargs)
      assert (
          "Failed to serialize the metric 'foo' to JSON"
          in checkpoint.validate()[0]
      )
  
      checkpoint = Checkpoint(
          metrics={"foo": "bar"},
          primary_metric={"name": "baz", "goal": "maximize"},
          **kwargs,
      )
      assert checkpoint.validate() == [
          "Primary metric 'baz' is not defined in metrics"
      ]
  
      checkpoint = Checkpoint(
          metrics={"foo": "bar"},
          primary_metric={"name": "foo", "goal": "maximilize"},
          **kwargs,
      )
      assert (
          "Primary metric goal must be either 'maximize' or 'minimize'"
          in checkpoint.validate()[0]
      )
  
      checkpoint = Checkpoint(path="..", **kwargs)
      assert (
          "The path passed to the checkpoint must not start with '..' or '/'."
          in checkpoint.validate()[0]
      )
      checkpoint = Checkpoint(path="/", **kwargs)
      assert (
          "The path passed to the checkpoint must not start with '..' or '/'."
          in checkpoint.validate()[0]
      )
      checkpoint = Checkpoint(path="blah", **kwargs)
      assert (
          "The path passed to the checkpoint does not exist: blah"
          in checkpoint.validate()[0]
      )
  
file_path: keepsake/python/tests/test_checkpoint.py
imports: import datetime
  import time
  import os
  import pytest
  from waiting import wait
  from keepsake.checkpoint import Checkpoint, CheckpointList
  from keepsake.exceptions import DoesNotExist
  from keepsake.project import Project
  from tests.factories import experiment_factory, checkpoint_factory
label_desc: Use image node_id 1 for calling the TestCheckpoint obj's underlying member method code with example usage: obj.test_validate() without return types