code: def test_memoryfile_tell(data_coutwildrnp_json):
      """Test MemoryFile.tell()"""
      with MemoryFile() as memfile:
          assert memfile.tell() == 0
          memfile.write(data_coutwildrnp_json)
          assert memfile.tell() == len(data_coutwildrnp_json)
  
imports: import os
  from io import BytesIO
  import pytest
  import fiona
  from fiona import supported_drivers
  from fiona.drvsupport import _driver_supports_mode
  from fiona.errors import DriverError
  from fiona.io import MemoryFile, ZipMemoryFile
  from fiona.meta import supports_vsi
  from .conftest import requires_gdal2, requires_gpkg
label_desc: Use image node_id 17 for calling a global function with example usage: test_memoryfile_tell(data_coutwildrnp_json) without return types