def _get_sfn_execution_arn_by_name(state_machine_arn, execution_name):
    """
    * Given a state machine arn and execution name, returns the execution's ARN
    * @param {string} state_machine_arn The ARN of the state machine containing the execution
    * @param {string} execution_name The name of the execution
    * @returns {string} The execution's ARN
    """
    return (':').join([state_machine_arn.replace(':stateMachine:', ':execution:'),
                       execution_name])