code: def test_get_from_env():
      with tempfile.TemporaryFile() as f:
          xtr = SupportMatrixExtractor("x", "22.02", f.name)
          xtr.get_from_env("SHELL")
          assert (
              xtr.data["x"]["22.02"].get("SHELL")
              != SupportMatrixExtractor.ERROR
          )
  
          xtr.get_from_env("SHELL", "shell")
          assert "shell" in xtr.data["x"]["22.02"].keys()
          assert (
              xtr.data["x"]["22.02"].get("shell")
              != SupportMatrixExtractor.ERROR
          )
  
          xtr.get_from_env("BAZ")
          assert "BAZ" in xtr.data["x"]["22.02"].keys()
          assert (
              xtr.data["x"]["22.02"].get("BAZ")
              == SupportMatrixExtractor.ERROR
          )
  
          xtr.get_from_env("BAZ", "bar")
          assert "bar" in xtr.data["x"]["22.02"].keys()
          assert (
              xtr.data["x"]["22.02"].get("bar")
              == SupportMatrixExtractor.ERROR
          )
  
          os.environ["SMX_COMPRESSED_SIZE"] = "7169310137"
          xtr.get_from_env("SMX_COMPRESSED_SIZE", "compressedSize")
          assert "compressedSize" in xtr.data["x"]["22.02"].keys()
          assert (
              xtr.data["x"]["22.02"].get("compressedSize") == "6.68 GB"
          )
          del os.environ["SMX_COMPRESSED_SIZE"]
  
file_path: Merlin/docs/test_extractor.py
imports: import json
  import os
  import shutil
  import tempfile
  from pathlib import Path
  from extractor import SupportMatrixExtractor
label_desc: Use image node_id 4 for calling a global function with example usage: test_get_from_env() without return types