Kivy uses built-in Vector class, resulting in truncate method not found

[vesauimonen]

Because Kivy uses its built-in Vector class, vectors such as

from .vector import Vector
vector = Vector(0, 0)
vector = vehicle.pos + another_vehicle.pos
vector = vector.truncate(10)
>>> AttributeError: 'Vector' object has no attribute 'truncate'

fail. This can be fixed by constructing the extended Vector class again:

from .vector import Vector
vector = Vector(0, 0) 
vector = vehicle.pos + another_vehicle.pos
vector = Vector(*vector).truncate(10)