code: def _extract_edge_map(c_edge_map):
      edge_map = {}
      for c_etype, emap in c_edge_map.items():
          etype = c_etype.split(":")[1]
          edge_map[etype] = emap
      return edge_map
  
file_path: dgl/tests/tools/test_change_etype_to_canonical_etype.py
imports: import json
  import os
  import tempfile
  import unittest
  from collections import Counter
  import dgl
  import pytest
  from change_etype_to_canonical_etype import convert_conf, is_old_version
  from dgl.distributed import partition_graph
  from scipy import sparse
label_desc: Use image node_id 7 for calling a global function with example usage: _extract_edge_map(c_edge_map) and returns: edge_map