Remove strings (presumably filenames) from 'files' that match
        'pattern'.

        Other parameters are the same as for 'include_pattern()', above.
        The list 'self.files' is modified in place. Return True if files are
        found.

        This API is public to allow e.g. exclusion of SCM subdirs, e.g. when
        packaging source distributions

def _exclude_pattern(self, pattern, anchor=True, prefix=None,
                         is_regex=False):
        """Remove strings (presumably filenames) from 'files' that match
        'pattern'.

        Other parameters are the same as for 'include_pattern()', above.
        The list 'self.files' is modified in place. Return True if files are
        found.

        This API is public to allow e.g. exclusion of SCM subdirs, e.g. when
        packaging source distributions
        """
        found = False
        pattern_re = self._translate_pattern(pattern, anchor, prefix, is_regex)
        for f in list(self.files):
            if pattern_re.search(f):
                self.files.remove(f)
                found = True
        return found