code: def state_machine_arn(self, state_machine_arn):
      self.state_machine_arn = state_machine_arn
      return self
  
file_path: metaflow/metaflow/plugins/aws/step_functions/event_bridge_client.py
imports: import base64
  import json
  from hashlib import sha1
  from metaflow.util import to_bytes, to_unicode
label_desc: Use image node_id 4 for calling the EventBridgeClient obj's underlying member method code with example usage: obj.state_machine_arn(state_machine_arn) and returns: self