docstr: Clean up and prepare one cluster for each mention
docstr_tok: ["Clean","up","and","prepare","one","cluster","for","each","mention"]
code: def _prepare_clusters(self):
      """
      Clean up and prepare one cluster for each mention
      """
      self.mention_to_cluster = list(
          list(range(len(doc_mentions))) for doc_mentions in self.m_loc
      )
      self.clusters = list(
          dict((i, [i]) for i in doc_mentions)
          for doc_mentions in self.mention_to_cluster
      )
  
imports: import os
  import subprocess
  import io
  import pickle
  import torch
  from torch.utils.data import DataLoader
  from neuralcoref.train.conllparser import FEATURES_NAMES
  from neuralcoref.train.dataset import NCBatchSampler, padder_collate
  from neuralcoref.train.compat import unicode_
label_desc: Use image node_id 3 for calling the ConllEvaluator obj's underlying member method code with example usage: obj._prepare_clusters() without return types