code: def deregister():
      
      # Renamed in pandas.plotting.__init__
      for type_, cls in get_pairs():
          # We use type to catch our classes directly, no inheritance
          if type(units.registry.get(type_)) is cls:
              units.registry.pop(type_)
  
      # restore the old keys
      for unit, formatter in _mpl_units.items():
          if type(formatter) not in {DatetimeConverter, PeriodConverter,
                                     TimeConverter}:
              # make it idempotent by excluding ours.
              units.registry[unit] = formatter
docs: Remove pandas' formatters and converters
  
      Removes the custom converters added by :func:`register`. This
      attempts to set the state of the registry back to the state before
      pandas registered its own units. Converters for pandas' own types like
      Timestamp and Period are removed completely. Converters for types
      pandas overwrites, like ``datetime.datetime``, are restored to their
      original value.
  
      See Also
      --------
      deregister_matplotlib_converters