code: def get(self, **wildcards):
      missing = self.rule.wildcard_names.difference(wildcards.keys())
      if missing:
          raise WorkflowError(
              "Missing wildcard values for {}".format(
                  ", ".join(missing)
              )
          )
  
      output, _ = self.rule.expand_output(wildcards)
      if self.checkpoints.future_output is not None:
          for iofile in output:
              if iofile in self.checkpoints.future_output:
                  break
          else:
              return CheckpointJob(self.rule, output)
  
      raise IncompleteCheckpointException(
          self.rule, checkpoint_target(output[0])
      )
  
file_path: snakemake/snakemake/checkpoints.py
imports: from snakemake.common import async_run
  from snakemake.exceptions import IncompleteCheckpointException, WorkflowError
  from snakemake.io import checkpoint_target
label_desc: Use image node_id 2 for calling the Checkpoint obj's underlying member method code with example usage: obj.get() and returns: CheckpointJob