code: def getSampleTypeTitles(self):
          
          sample_types = self.getSampleTypes()
          sample_type_titles = map(lambda obj: obj.Title(), sample_types)
  
          # N.B. This is used only for search purpose, because the catalog does
          #      not add an entry to the Keywordindex for an empty list.
          #
          # => This "empty" category allows to search for values with a certain
          #    sample type set OR with no sample type set.
          #    (see bika.lims.browser.analysisrequest.add2.get_sampletype_info)
          if not sample_type_titles:
              return [""]
          return sample_type_titles
docs: Returns a list of sample type titles