docstr: Prior to v2 format CRC was contained in every message. This will
  be the checksum for v0 and v1 and None for v2 and above.
docstr_tok: ["Prior","to","v2","format","CRC","was","contained","in","every","message",".","This","will","be","the","checksum","for","v0","and","v1","and","None","for","v2","and","above","."]
code: def checksum(self):
      """Prior to v2 format CRC was contained in every message. This will
      be the checksum for v0 and v1 and None for v2 and above.
      """
  
imports: from __future__ import absolute_import
  import abc
label_desc: Use image node_id 6 for calling the ABCRecord obj's underlying member method code with example usage: obj.checksum() without return types