'Return a list of preprocessors to apply to the given event.
A preprocessor is a function that takes the normalized data blob as an
input and returns modified data as output. If no changes to the data are
made it is safe to return ``None``.
Preprocessors should not be returned if there is nothing to
do with the event data.
>>> def get_event_preprocessors(self, data, **kwargs):
>>>     return [lambda x: x]'

def get_event_preprocessors(self, data, **kwargs):

    return []
