code: def _setup_dtype(self):
          
          if self._dtype is not None:
              return self._dtype
  
          dtype = []  # Convert struct data types to numpy data type
          for i, typ in enumerate(self.typlist):
              if typ in self.NUMPY_TYPE_MAP:
                  dtype.append(('s' + str(i), self.byteorder +
                                self.NUMPY_TYPE_MAP[typ]))
              else:
                  dtype.append(('s' + str(i), 'S' + str(typ)))
          dtype = np.dtype(dtype)
          self._dtype = dtype
  
          return self._dtype
docs: Map between numpy and state dtypes