code: def test_clang_format():
      """Check coding style for cpp files."""
      clang_format = "clang-format-3.6"
      try:
          subprocess.check_call([clang_format, "--version"])
      except OSError:
          raise unittest.SkipTest(clang_format + " not available")
  
      pythran_dir = os.path.abspath(
          os.path.dirname(os.path.dirname(__file__))
      )
      for root, _, _ in os.walk(os.path.join(pythran_dir, "pythonic")):
          for file_ in glob.glob(os.path.join(root, "*.hpp")):
              if os.path.basename(file_) in excluded_files:
                  continue
              cmd = "{cmd} {file} | diff -u {file} -".format(
                  cmd=clang_format, file=os.path.join(root, file_)
              )
              process = subprocess.Popen(
                  cmd,
                  shell=True,
                  stdout=subprocess.PIPE,
                  universal_newlines=True,
              )
              assert not process.wait(), process.stdout.read()
  
imports: import glob
  import os
  import subprocess
  import unittest
label_desc: Use image node_id 1 for calling a global function with example usage: test_clang_format() without return types