code: def deprecated(func):
      
  
      @functools.wraps(func)
      def new_func(*args, **kwargs):
          if PY3K:
              func_code = func.__code__
          else:
              func_code = func.func_code
  
          warnings.warn_explicit(
              "Call to deprecated function {}.".format(func.__name__),
              category=DeprecationWarning,
              filename=func_code.co_filename,
              lineno=func_code.co_firstlineno + 1,
          )
  
          return func(*args, **kwargs)
  
      return new_func
docs: This is a decorator which can be used to mark functions
      as deprecated. It will result in a warning being emitted
      when the function is used.