Memory explosion

[UPUPGOO]

I want to test my robot in different terrains. So I create these terrains using the Python function createCollisionShape and destroy them using the function removeBody. However, when creating and destroying objects frequently, memory usage increased rapidly.

The minimal code is provided below.

import pybullet as p
import numpy as np
import psutil

p.connect(p.DIRECT)

def f():
    height_field = np.zeros((1000, 1000))
    terrain_shape = p.createCollisionShape(
        shapeType=p.GEOM_HEIGHTFIELD,
        heightfieldData=height_field.transpose().flatten(),
        numHeightfieldRows=height_field.shape[0],
        numHeightfieldColumns=height_field.shape[1])
    terrain_id = p.createMultiBody(baseMass=0,
                                   baseCollisionShapeIndex=terrain_shape,
                                   basePosition=(0, 0, 0))
    p.removeBody(terrain_id)

for i in range(1000):
    f()
    mem = psutil.virtual_memory()
    print(f"Epoch {i}: {mem.used / 1024 / 1024:.1f}MB ({mem.percent}%)")

The results are:

Version:
- pybullet: 3.0.8
- numpy: 1.20.1

Is it possible to release the memory when destroyed the objects?
Any help is appreciated.

--------------------------------update------------------------------
I also tried to remove the collision shape using the function removeCollisionShape, but I failed.
The terminal gave me a warning message as shown below.