old_contents: import os
  from subprocess import check_call
  
  REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
  os.chdir(REPO_ROOT)
  
  os.putenv(
      "PATH", "{}:{}".format(os.path.join(REPO_ROOT, "bin"), os.getenv("PATH"))
  )
  os.putenv("DVC_HOME", REPO_ROOT)
  os.putenv("DVC_TEST", "true")
  
  cmd = (
      "nosetests -v --processes=-1 --process-timeout=500 --cover-inclusive "
      "--cover-erase --cover-package=dvc --with-coverage --all-modules --with-flaky"
  )
  check_call(cmd, shell=True)
  
new_contents: import os
  import sys
  from subprocess import check_call
  
  
  REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
  os.chdir(REPO_ROOT)
  
  os.putenv(
      "PATH", "{}:{}".format(os.path.join(REPO_ROOT, "bin"), os.getenv("PATH"))
  )
  os.putenv("DVC_HOME", REPO_ROOT)
  os.putenv("DVC_TEST", "true")
  
  if len(sys.argv) == 1:
      scope = "--all-modules"
  else:
      scope = " ".join(sys.argv[1:])
  
  cmd = (
      "nosetests -v --processes=-1 --process-timeout=500 --cover-inclusive "
      "--cover-erase --cover-package=dvc --with-coverage --with-flaky "
      "{scope} ".format(scope=scope)
  )
  check_call(cmd, shell=True)
  
subject: add ability run tests from specified file(s)