old_contents: from thinglang.compiler.opcodes import MEMBERS, METHODS, FRAME_SIZE, ARGUMENTS
  from thinglang.compiler.opcodes import Opcode
  
  
  class SentinelThingDefinition(Opcode):
      """
      Signifies the start of thing definition
      """
      ARGS = MEMBERS, METHODS
  
  
  class SentinelMethodDefinition(Opcode):
      """
      Signifies a method definition boundary.
      """
      ARGS = FRAME_SIZE, ARGUMENTS
  
  
  class SentinelMethodEnd(Opcode):
      """
      Signifies a method boundary.
      """
      pass
  
  
  class SentinelCodeEnd(Opcode):
      """
      Signifies the code section boundary.
      """
      pass
  
  
  class SentinelDataEnd(Opcode):
      """
      Signifies the code section boundary.
      """
      pass
  
new_contents: from thinglang.compiler.opcodes import MEMBERS, METHODS, FRAME_SIZE, ARGUMENTS
  from thinglang.compiler.opcodes import Opcode
  
  
  class SentinelImportTableEntry(Opcode):
      """
      Signifies an import table entry
      """
  
  
  class SentinelImportTableEnd(Opcode):
      """
      Signifies the end of the import table
      """
  
  
  class SentinelThingDefinition(Opcode):
      """
      Signifies the start of thing definition
      """
      ARGS = MEMBERS, METHODS
  
  
  class SentinelMethodDefinition(Opcode):
      """
      Signifies a method definition boundary.
      """
      ARGS = FRAME_SIZE, ARGUMENTS
  
  
  class SentinelMethodEnd(Opcode):
      """
      Signifies a method boundary.
      """
      pass
  
  
  class SentinelCodeEnd(Opcode):
      """
      Signifies the code section boundary.
      """
      pass
  
  
  class SentinelDataEnd(Opcode):
      """
      Signifies the code section boundary.
      """
      pass
  
subject: Add serialization sentintels for import table