code: def test_tin_csv(path_test_tin_csv):
      """Convert TIN to MultiPolygon and Triangle to Polygon"""
      with fiona.open(path_test_tin_csv) as col:
          assert col.schema["geometry"] == "Unknown"
  
          feature1 = next(col)
          _test_tin(feature1["geometry"])
  
          feature2 = next(col)
          _test_triangle(feature2["geometry"])
  
          feature3 = next(col)
          assert feature3["geometry"]["type"] == "GeometryCollection"
          assert len(feature3["geometry"]["geometries"]) == 2
  
          _test_tin(feature3["geometry"]["geometries"][0])
          _test_triangle(feature3["geometry"]["geometries"][1])
  
imports: import fiona
  from fiona.model import Geometry
label_desc: Use image node_id 4 for calling a global function with example usage: test_tin_csv(path_test_tin_csv) without return types