code: def test_itemcoverage(self):
      name = "itemcoverage"
      Metric = metrics_dict[name](config)
      self.assertEqual(
          Metric.get_coverage(item_matrix, num_items), 7 / 8
      )
  
file_path: RecBole/tests/metrics/test_topk_metrics.py
imports: import os
  import sys
  import unittest
  import numpy
  from recbole.config import Config
  from recbole.evaluator.register import metrics_dict
label_desc: Use image node_id 7 for calling the TestTopKMetrics obj's underlying member method code with example usage: obj.test_itemcoverage() without return types