code: def _format_keyword(self, keyword):
          
          import re
          result = ''
          if keyword:
              result = re.sub(r"\W", "", keyword)
              # Remove underscores ('_') too.
              result = re.sub(r"_", "", result)
          return result
docs: Removing special character from a keyword. Analysis Services must have
          this kind of keywords. E.g. if assay name from GeneXpert Instrument is
          'Ebola RUO', an AS must be created on Bika with the keyword 'EbolaRUO'