code: def test_free_different_size(self):
      p1 = self.pool.malloc(1000)
      ptr1 = p1.ptr
      del p1
      p2 = self.pool.malloc(2000)
      assert ptr1 != p2.ptr
  
imports: import unittest
  from cupy.cuda import pinned_memory
label_desc: Use image node_id 4 for calling the TestSingleDeviceMemoryPool obj's underlying member method code with example usage: obj.test_free_different_size() without return types