code: def filename_json(tmpdir):
      return str(tmpdir.join("example.json"))
  
imports: import fiona
  import pytest
  from fiona.errors import GeometryTypeValidationError, UnsupportedGeometryTypeError
  from fiona.model import Feature
label_desc: Use image node_id 2 for calling a global function with example usage: filename_json(tmpdir) and returns: str