code: def populateFromHeader(self, readGroupHeader):
          
          self._sampleName = readGroupHeader.get('SM', None)
          self._description = readGroupHeader.get('DS', None)
          if 'PI' in readGroupHeader:
              self._predictedInsertSize = int(readGroupHeader['PI'])
          self._instrumentModel = readGroupHeader.get('PL', None)
          self._sequencingCenter = readGroupHeader.get('CN', None)
          self._experimentDescription = readGroupHeader.get('DS', None)
          self._library = readGroupHeader.get('LB', None)
          self._platformUnit = readGroupHeader.get('PU', None)
          self._runTime = readGroupHeader.get('DT', None)
docs: Populate the instance variables using the specified SAM header.