def __init__(self, time_series_a, time_series_b, max_shift_seconds=None, shift_impact=None):
super(CrossCorrelator, self).__init__(self.__class__.__name__, time_series_a, time_series_b)<EOL>self.shift_impact = shift_impact or DEFAULT_SHIFT_IMPACT<EOL>if max_shift_seconds is not None:<EOL><INDENT>self.max_shift_milliseconds = max_shift_seconds<EOL><DEDENT>else:<EOL><INDENT>self.max_shift_milliseconds = DEFAULT_ALLOWED_SHIFT_SECONDS * <NUM_LIT:1000><EOL><DEDENT>
Initializer
:param TimeSeries time_series_a: TimeSeries a.
:param TimeSeries time_series_b: TimeSeries b.
:param int max_shift_milliseconds: allowed maximal shift seconds.
:param time_period: if given, correlate the data inside the time period only.