How to get/modify individually vertex position of imported face mesh object?

I'm using a custom face-mesh object exported from blender.
I can change/modify translation, scale, and rotation of the mesh as follows.
'''
// @input SceneObject face_object

script.face_object.getTransform().getLocalPosition()
script.face_object.getTransform().getLocalScale()

pos = new vec3(0,7,0)
script.face_object.getTransform().setLocalPosition(pos)

scale = new vec3(2,2,2)
script.face_object.getTransform().setLocalScale(scale)

'''

However, I couldn't find how to get/modify each vertex location in script.

MeshBuilder seems to be used for mesh generation.
How can I individually get or modify vertex location of the imported face-mesh object in script?

Thank you.