class_docstr: Mark a function or class as deprecated (decorator).
  
  Issue a warning when the function is called/the class is instantiated and
  adds a warning to the docstring.
  
  The optional extra argument will be appended to the deprecation message
  and the docstring. Note: to use this with the default value for extra, put
  in an empty of parentheses::
  
      >>> from pyriemann.utils import deprecated
      >>> deprecated()
      <pyriemann.utils.docs.deprecated object at ...>
      >>> @deprecated()
      ... def some_function(): pass
  
  
  Parameters
  ----------
  extra: string
      To be added to the deprecation messages.
docstr: Decorate function fun.
docstr_tok: ["Decorate","function","fun","."]
code: def _decorate_fun(self, fun):
      """Decorate function fun."""
      msg = "Function %s is deprecated" % fun.__name__
      if self.extra:
          msg += "; %s" % self.extra
  
      def deprecation_wrapped(*args, **kwargs):
          warnings.warn(msg, category=DeprecationWarning)
          return fun(*args, **kwargs)
  
      deprecation_wrapped.__name__ = fun.__name__
      deprecation_wrapped.__dict__ = fun.__dict__
      deprecation_wrapped.__doc__ = self._update_doc(fun.__doc__)
  
      return deprecation_wrapped
  
file_path: pyRiemann/pyriemann/utils/docs.py
imports: import warnings
label_desc: Use image node_id 4 for calling the deprecated obj's underlying member method code with example usage: obj._decorate_fun(fun) and returns: deprecation_wrapped, fun