'Abstract method, which should return the date for a log line
This should return the date for a log line, typically taking the
date from the part of the line which matched the templates regex.
This requires abstraction, therefore just raises exception.
Parameters
line : str
Log line, of which the date should be extracted from.
default_tz: if no explicit time zone is present in the line
passing this will interpret it as in that time zone.
Raises
NotImplementedError
Abstract method, therefore always returns this.'

@abstractmethod
def getDate(self, line, dateMatch=None, default_tz=None):

    raise NotImplementedError('getDate()    is    abstract')
