docs: def detectionLimit(self):
          """
          Detection limit for parasitaemia
          Limit above which a human's infection is reported as patent
          https://github.com/SwissTPH/openmalaria/wiki/GeneratedSchema32Doc#detection-limit-for-parasitaemia
          """
          surveys_elem = self.et.find("surveys")
          if surveys_elem is None:
              return None
  
          try:
              detectionLimit = float(surveys_elem.attrib["detectionLimit"])
          except KeyError:
              detectionLimit = None
          return detectionLimit