code: def _get_unsorted_nested_struct_fields(elements: dict):
      unsorted_fields = [
          elements["_id"],
          elements["first_name"],
          StructField(
              "address",
              StructType(
                  [
                      StructField(
                          "zip",
                          StructType(
                              [elements["last4"], elements["first5"]]
                          ),
                          nullable=True,
                      ),
                      elements["city"],
                  ]
              ),
              nullable=True,
          ),
      ]
      return unsorted_fields
  
imports: from __future__ import annotations
  import pytest
  import chispa
  import quinn
  from pyspark.sql import DataFrame
  from pyspark.sql.types import StructType, StructField, StringType, IntegerType, ArrayType, MapType
  from quinn.transformations import flatten_struct, flatten_map, flatten_dataframe
  from tests.conftest import auto_inject_fixtures
label_desc: Use image node_id 10 for calling a global function with example usage: _get_unsorted_nested_struct_fields(elements) and returns: unsorted_fields