class_docstr: Unit test class for an already trained model.
class_docstr_tok: ["Unit","test","class","for","an","already","trained","model","."]
code: def test_export_coreml(self):
      import platform
      import coremltools
  
      filename = tempfile.NamedTemporaryFile(suffix=".mlmodel").name
      self.model.export_coreml(filename)
  
      coreml_model = coremltools.models.MLModel(filename)
      metadata = coreml_model.user_defined_metadata
  
      self.assertEqual(
          metadata["com.github.apple.turicreate.version"],
          tc.__version__,
      )
      self.assertEqual(
          metadata["com.github.apple.os.platform"], platform.platform()
      )
      self.assertEqual(metadata["type"], self.model.__class__.__name__)
  
      expected_result = (
          "Text classifier created by Turi Create (version %s)"
          % tc.__version__
      )
      self.assertEquals(expected_result, coreml_model.short_description)
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import tempfile
  import turicreate
  from turicreate.toolkits._main import ToolkitError
  from turicreate.toolkits._internal_utils import _mac_ver
  from .None import util
  import sys
label_desc: Use image node_id 7 for calling the TextClassifierTest obj's underlying member method code with example usage: obj.test_export_coreml() without return types