code: def test_classify_type():
      assert utils.classify_type("string") == "S"
      assert utils.classify_type("boolean") == "B"
      assert utils.classify_type("float64") == "F"
      assert utils.classify_type("integer64") == "I"
      assert utils.classify_type("timestamp") == "D"
      assert utils.classify_type("timedelta") == "TD"
      assert utils.classify_type("foo") == "S"
  
file_path: dtale/tests/dtale/test_utils.py
imports: from collections import namedtuple
  import mock
  import numpy
  import pandas
  import pytest
  from six import PY3
  import dtale.utils
  from tests import ExitStack
label_desc: Use image node_id 7 for calling a global function with example usage: test_classify_type() without return types