docs: def find_executable(executable_name):
      """Tries to find executable in PATH environment
  
      It uses ``shutil.which`` method in Python3 and
      ``distutils.spawn.find_executable`` method in Python2.7 to find the
      absolute path to the 'name' executable.
      :param executable_name: name of the executable
      :returns: Returns the absolute path to the executable or None if not found.
      """
      if six.PY3:
          executable_abs = shutil.which(executable_name)
      else:
          import distutils.spawn
          executable_abs = distutils.spawn.find_executable(executable_name)
  
      return executable_abs