def _find_first_bigger(self, timestamps, target, lower_bound, upper_bound):
while lower_bound < upper_bound:<EOL><INDENT>pos = lower_bound + (upper_bound - lower_bound) / <NUM_LIT:2><EOL>if timestamps[pos] > target:<EOL><INDENT>upper_bound = pos<EOL><DEDENT>else:<EOL><INDENT>lower_bound = pos + <NUM_LIT:1><EOL><DEDENT><DEDENT>return pos<EOL>
Find the first element in timestamps whose value is bigger than target.
param list values: list of timestamps(epoch number).
param target: target value.
param lower_bound: lower bound for binary search.
param upper_bound: upper bound for binary search.