code: def check_street_suffix(self, token):
          
          # Suffix must come before street
          # print "Suffix check", token, "suffix", self.street_suffix, "street", self.street
          if self.street_suffix is None and self.street is None:
              # print "upper", token.upper()
              if token.upper() in self.parser.suffixes.keys():
                  suffix = self.parser.suffixes[token.upper()]
                  self.street_suffix = self._clean(suffix.capitalize() + '.')
                  return True
              elif token.upper() in self.parser.suffixes.values():
                  self.street_suffix = self._clean(token.capitalize() + '.')
                  return True
          return False
docs: Attempts to match a street suffix. If found, it will return the abbreviation, with the first letter capitalized
          and a period after it. E.g. "St." or "Ave."