class_docstr: Implement a ketama compatible consistent hashing ring.
docstr: Remove the given node from the continuum/ring.
  
  :param node_name: the node name.
code: def _remove_node(self, node_name):
      """Remove the given node from the continuum/ring.
  
      :param node_name: the node name.
      """
      try:
          self._nodes.pop(node_name)
      except Exception:
          raise KeyError(
              f"node '{node_name}' not found, "
              f"available nodes: {list(self._nodes.keys())}"
          )
      else:
          self._create_ring(self._nodes)
  
file_path: mars/mars/lib/uhashring/ring_ketama.py
imports: from bisect import insort
  from collections import Counter
  from hashlib import md5
  from sys import version_info
label_desc: Use image node_id 6 for calling the KetamaRing obj's underlying member method code with example usage: obj._remove_node(node_name) without return types