code: def __init__(self, *args, **kwargs):
      super(LangchainTransformTest, self).__init__(*args, **kwargs)
      # fetching openai_api_key
      secretJson = subprocess.check_output(
          "az keyvault secret show --vault-name mmlspark-build-keys --name openai-api-key",
          shell=True,
      )
      openai_api_key = json.loads(secretJson)["value"]
      openai_api_base = "https://synapseml-openai.openai.azure.com/"
      openai_api_version = "2022-12-01"
      openai_api_type = "azure"
  
      os.environ["OPENAI_API_TYPE"] = openai_api_type
      os.environ["OPENAI_API_VERSION"] = openai_api_version
      os.environ["OPENAI_API_BASE"] = openai_api_base
      os.environ["OPENAI_API_KEY"] = openai_api_key
  
      self.subscriptionKey = openai_api_key
      self.url = openai_api_base
  
      # construction of llm
      llm = AzureOpenAI(
          deployment_name="text-davinci-003",
          model_name="text-davinci-003",
          temperature=0,
          verbose=False,
      )
  
      # construction of Chain
      # It is a very simple chain, basically just
      # expand the input column and then summarize to the output column
      # output column should be very similar to input column,
      # and should contain the words input column
      copy_prompt = PromptTemplate(
          input_variables=["technology"],
          template="Copy the following word: {technology}",
      )
  
      self.chain = LLMChain(llm=llm, prompt=copy_prompt)
      self.langchainTransformer = (
          LangchainTransformer()
          .setInputCol("technology")
          .setOutputCol("copied_technology")
          .setChain(self.chain)
          .setSubscriptionKey(self.subscriptionKey)
          .setUrl(self.url)
      )
  
      # construction of test dataframe
      self.sentenceDataFrame = spark.createDataFrame(
          [(0, "docker"), (0, "spark"), (1, "python")],
          ["label", "technology"],
      )
  
file_path: SynapseML/cognitive/src/test/python/synapsemltest/services/langchain/test_LangchainTransform.py
imports: import os, json, subprocess, unittest
  from langchain.chains import LLMChain
  from langchain.prompts import PromptTemplate
  from langchain.llms import AzureOpenAI
  from synapse.ml.services.langchain import LangchainTransformer
  from synapsemltest.spark import *
label_desc: Use image node_id 1 to create a new LangchainTransformTest object from inherited base classes: unittest with example: obj = LangchainTransformTest()