class_docstr: DenStream Micro-cluster class
code: def insert(self, x, timestamp):
      self.N += 1
      self.last_edit_time = timestamp
      for key, val in x.items():
          try:
              self.linear_sum[key] += val
              self.squared_sum[key] += val * val
          except KeyError:
              self.linear_sum[key] = val
              self.squared_sum[key] = val * val
  
imports: from __future__ import annotations
  import copy
  import math
  from abc import ABCMeta
  from collections import defaultdict, deque
  from river import base, utils
label_desc: Use image node_id 7 for calling the DenStreamMicroCluster obj's underlying member method code with example usage: obj.insert(x, timestamp) without return types