code: def magics_class(cls):
      """Class decorator for all subclasses of the main Magics class.
  
      Any class that subclasses Magics *must* also apply this decorator, to
      ensure that all the methods that have been decorated as line/cell magics
      get correctly registered in the class instance.  This is necessary because
      when method decorators run, the class does not exist yet, so they
      temporarily store their information into a module global.  Application of
      this class decorator copies that global data to the class instance and
      clears the global.
  
      Obviously, this mechanism is not thread-safe, which means that the
      *creation* of subclasses of Magic should only be done in a single-thread
      context.  Instantiation of the classes has no restrictions.  Given that
      these classes are typically created at IPython startup time and before user
      application code becomes active, in practice this should not pose any
      problems.
      """
      cls.registered = True
      cls.magics = dict(line=magics["line"], cell=magics["cell"])
      magics["line"] = {}
      magics["cell"] = {}
      return cls
  
imports: from __future__ import print_function
  import os
  import re
  import sys
  import types
  from getopt import getopt, GetoptError
  from traitlets.config.configurable import Configurable
  from IPython.core import oinspect
  from IPython.core.error import UsageError
  from IPython.core.inputsplitter import ESC_MAGIC, ESC_MAGIC2
  from decorator import decorator
  from IPython.utils.ipstruct import Struct
  from IPython.utils.process import arg_split
  from IPython.utils.py3compat import string_types, iteritems
  from IPython.utils.text import dedent
  from traitlets import Bool, Dict, Instance, observe
  from logging import error
label_desc: Use image node_id 4 for calling a global function with example usage: magics_class(cls) and returns: cls