'Sets the error-message filters.
These filters are applied when deciding whether to emit a given
error message.
Args:
filters: A string of comma-separated filters (eg "+whitespace/indent").
Each filter should start with + or -; else we die.
Raises:
ValueError: The comma-separated filters did not all start with \'+\' or \'-\'.
E.g. "-,+whitespace,-whitespace/indent,whitespace/badfilter"'

def SetFilters(self, filters):

    self.filters = _DEFAULT_FILTERS[:]
    for filt in filters.split(','):
        clean_filt = filt.strip()
        if clean_filt:
            self.filters.append(clean_filt)
    for filt in self.filters:
        if (not (filt.startswith('+') or filt.startswith('-'))):
            raise ValueError(('Every    filter    in    --filters    must    start    with    +    or    -    (%s    does    not)' % filt))
