def METHOD_NAME(T1 : RigidTransform, T2 : RigidTransform, Rweight=1.0,tweight=1.0) -> float:
    """Returns a distance metric between the two transformations. The
    rotation distance is weighted by Rweight and the translation distance
    is weighted by tweight"""
    (R1,t1)=T1
    (R2,t2)=T2
    return Rweight*so3.METHOD_NAME(R1,R2) + tweight*vectorops.METHOD_NAME(t1,t2)