code: def test_get_conn(self, engine_postgis):
      Connection = pytest.importorskip(
          "sqlalchemy.engine.base"
      ).Connection
  
      engine = engine_postgis
      with get_conn(engine) as output:
          assert isinstance(output, Connection)
      with engine.connect() as conn:
          with get_conn(conn) as output:
              assert isinstance(output, Connection)
      with pytest.raises(ValueError):
          with get_conn(object()):
              pass
  
imports: import os
  import warnings
  import pandas
  import geopandas
  from geopandas import GeoDataFrame, read_file, read_postgis
  import geopandas._compat
  from geopandas.io.sql import _get_conn, _write_postgis
  from geopandas.tests.util import create_postgis, create_spatialite, validate_boro_df
  import pytest
label_desc: Use image node_id 1 for calling the TestIO obj's underlying member method code with example usage: obj.test_get_conn(engine_postgis) without return types