<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_trial(self, tid):
 """Retrieve trial by tid """

        lid = np.where(np.array(self.tids) == tid)[0][0]
        return self.trials[lid]