code: def to_yaml(self, path):
      with open(path, "w") as f:
          # Exclude None and empty lists
          data = {k: v for k, v in self.to_dict().items() if v}
          yaml.safe_dump(
              data, f, sort_keys=False, default_flow_style=False
          )
  
imports: import logging
  import os
  import re
  import subprocess
  import sys
  import tempfile
  import yaml
  from packaging.requirements import InvalidRequirement, Requirement
  from packaging.version import Version
  from mlflow.environment_variables import _MLFLOW_TESTING
  from mlflow.exceptions import MlflowException
  from mlflow.protos.databricks_pb2 import INVALID_PARAMETER_VALUE
  from mlflow.utils import PYTHON_VERSION, insecure_hash
  from mlflow.utils.process import _exec_cmd
  from mlflow.utils.requirements_utils import _infer_requirements, _parse_requirements
  from mlflow.version import VERSION
label_desc: Use image node_id 8 for calling the _PythonEnv obj's underlying member method code with example usage: obj.to_yaml(path) without return types