old_contents: from __future__ import absolute_import, division, print_function
  from builtins import str
  
  from panoptes_client.panoptes import Panoptes, PanoptesObject
  from panoptes_client.workflow import Workflow
  
  class WorkflowVersion(PanoptesObject):
      _api_slug = 'versions'
      _edit_attributes = tuple()
  
      @classmethod
      def http_get(cls, path, params={}, headers={}):
          workflow = params.pop('workflow')
          return Panoptes.client().get(
              Workflow.url(workflow.id) + cls.url(path),
              params,
              headers,
          )
  
      def save(self):
          raise NotImplementedError(
              'It is not possible to manually create workflow versions. '
              'Modify the workflow instead.'
          )
  
      @property
      def workflow(self):
          return self.links.item
  
new_contents: from __future__ import absolute_import, division, print_function
  
  from panoptes_client.panoptes import (
      Panoptes,
      PanoptesAPIException,
      PanoptesObject,
  )
  from panoptes_client.workflow import Workflow
  
  
  class WorkflowVersion(PanoptesObject):
      _api_slug = 'versions'
      _edit_attributes = tuple()
  
      @classmethod
      def http_get(cls, path, params={}, headers={}):
          workflow = params.pop('workflow')
          return Panoptes.client().get(
              Workflow.url(workflow.id) + cls.url(path),
              params,
              headers,
          )
  
      @classmethod
      def find(cls, _id, workflow):
          try:
              return cls.where(id=_id, workflow=workflow).next()
          except StopIteration:
              raise PanoptesAPIException(
                  "Could not find {} with id='{}'".format(cls.__name__, _id)
              )
  
      def save(self):
          raise NotImplementedError(
              'It is not possible to manually create workflow versions. '
              'Modify the workflow instead.'
          )
  
      @property
      def workflow(self):
          return self.links.item
  
subject: Add working WorkflowVersion.find() method