code: def test_update_leaf(self):
      h = [0, 20, 10, 60, 30, 50, 40]
      h_updated = [0, 15, 10, 60, 20, 50, 40]
      q = self._make_mapped_queue(h)
      removed = q.update(30, 15)
      assert q.heap == h_updated
  
imports: import pytest
  from networkx.utils.mapped_queue import MappedQueue, _HeapElement
label_desc: Use image node_id 21 for calling the TestMappedQueue obj's underlying member method code with example usage: obj.test_update_leaf() without return types