code: def testSetValueSmallCapacity(self):
      tree = sum_tree.SumTree(capacity=1)
      tree.set(0, 1.5)
      self.assertEqual(tree.get(0), 1.5)
  
imports: import random
  import unittest
  from reagent.replay_memory import sum_tree
label_desc: Use image node_id 5 for calling the SumTreeTest obj's underlying member method code with example usage: obj.testSetValueSmallCapacity() without return types