code: def test_session_aws_or_dummy_dummy(monkeypatch):
      """Get a DummySession when boto3 is not available"""
      boto3 = pytest.importorskip("boto3")
      with monkeypatch.context() as mpctx:
          mpctx.setattr("rasterio.session.boto3", None)
          assert isinstance(Session.aws_or_dummy(), DummySession)
  
imports: from unittest import mock
  import pytest
  from rasterio.session import DummySession, AWSSession, Session, OSSSession, GSSession, SwiftSession, AzureSession, parse_bool
label_desc: Use image node_id 30 for calling a global function with example usage: test_session_aws_or_dummy_dummy(monkeypatch) without return types