code: def test_annotation_post_schema_basic() -> None:
      result = AnnotationPostSchema().load(
          {
              "short_descr": "foo",
              "start_dttm": START_STR,
              "end_dttm": END_STR,
          }
      )
      assert result["short_descr"] == "foo"
      assert result["start_dttm"] == START_DTTM
      assert result["end_dttm"] == END_DTTM
  
imports: import pytest
  from marshmallow.exceptions import ValidationError
  from superset.annotation_layers.annotations.schemas import AnnotationPostSchema, AnnotationPutSchema
  from superset.annotation_layers.schemas import AnnotationLayerPostSchema, AnnotationLayerPutSchema
  from tests.unit_tests.annotation_layers.fixtures import END_DTTM, END_STR, START_DTTM, START_STR
label_desc: Use image node_id 8 for calling a global function with example usage: test_annotation_post_schema_basic() without return types