code: def load_file(self, file_handle, data_set=0, read_data=True):
          
          file_handle.seek(0, 2)
          self._file_size = file_handle.tell()
          file_handle.seek(0)
          data_segments = 0
          # seek the correct data set in fcs
          nextdata_offset = 0
          while data_segments <= data_set:
              self.read_header(file_handle, nextdata_offset)
              self.read_text(file_handle)
              if '$NEXTDATA' in self.annotation:
                  data_segments += 1
                  nextdata_offset = self.annotation['$NEXTDATA']
                  file_handle.seek(nextdata_offset)
                  if nextdata_offset == 0 and data_segments < data_set:
                      warnings.warn("File does not contain the number of data sets.")
                      break
              else:
                  if data_segments != 0:
                      warnings.warn('File does not contain $NEXTDATA information.')
                  break
          if read_data:
              self.read_data(file_handle)
docs: Load the requested parts of the file into memory.