class_docstr: A statistic.
code: def __repr__(self):
      try:
          value = self.get()
      except NotImplementedError:
          value = None
      fmt_value = (
          None if value is None else f"{value:{self._fmt}}".rstrip("0")
      )
      return f"{self.__class__.__name__}: {fmt_value}"
  
imports: from __future__ import annotations
  import abc
  import numbers
  from river import base
label_desc: Use image node_id 2 for calling the Statistic obj's underlying member method code with example usage: obj.__repr__() and returns: self, str, fmt_value