<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def gate_angle(gate0: Gate, gate1: Gate) -> bk.BKTensor: """The Fubini-Study angle between gates"""

    return fubini_study_angle(gate0.vec, gate1.vec)