code: def test_get_schema_from_dataset_url(synthetic_dataset):
      schema = get_schema_from_dataset_url(synthetic_dataset.url)
      assert TestSchema.fields == schema.fields
  
file_path: petastorm/petastorm/tests/test_dataset_metadata.py
imports: import numpy
  import pytest
  import pyarrow
  from pyspark.sql import SparkSession
  from pyspark.sql.types import IntegerType
  from petastorm.codecs import ScalarCodec
  from petastorm.etl.dataset_metadata import get_schema_from_dataset_url, materialize_dataset
  from petastorm.tests.test_common import TestSchema
  from petastorm.unischema import Unischema, UnischemaField, dict_to_spark_row
label_desc: Use image node_id 1 for calling a global function with example usage: test_get_schema_from_dataset_url(synthetic_dataset) without return types