How to use the brewtils.choices.parse function in brewtils

f"not a string or dict"
            )

        if self.type == "command" and isinstance(self.value, dict):
            value_keys = self.value.keys()
            for required_key in ("command", "system", "version"):
                if required_key not in value_keys:
                    raise ModelValidationError(
                        f"Can not save choices '{self}': specifying value as a "
                        f"dictionary requires a '{required_key}' item"
                    )

        try:
            if self.details == {}:
                if isinstance(self.value, six.string_types):
                    self.details = parse(self.value)
                elif isinstance(self.value, dict):
                    self.details = parse(self.value["command"])
        except (LarkError, ParseError):
            raise ModelValidationError(
                f"Can not save choices '{self}': Unable to parse"
            )

else:
                    raise ModelValidationError(
                        "Unable to validate choices for parameter '%s' - Choices value"
                        " must be a list or dictionary " % command_parameter.key
                    )
            elif choices.type == "url":
                parsed_value = parse(choices.value, parse_as="url")
                query_params = map_param_values(parsed_value["args"])

                raw_allowed = json.loads(
                    self._session.get(parsed_value["address"], params=query_params).text
                )
            elif choices.type == "command":

                if isinstance(choices.value, six.string_types):
                    parsed_value = parse(choices.value, parse_as="func")

                    choices_request = Request(
                        system=request.system,
                        system_version=request.system_version,
                        instance_name=request.instance_name,
                        command=parsed_value["name"],
                        parameters=map_param_values(parsed_value["args"]),
                    )
                elif isinstance(choices.value, dict):
                    parsed_value = parse(choices.value["command"], parse_as="func")
                    choices_request = Request(
                        system=choices.value.get("system"),
                        system_version=choices.value.get("version"),
                        instance_name=choices.value.get("instance_name", "default"),
                        command=parsed_value["name"],
                        parameters=map_param_values(parsed_value["args"]),

self._session.get(parsed_value["address"], params=query_params).text
                )
            elif choices.type == "command":

                if isinstance(choices.value, six.string_types):
                    parsed_value = parse(choices.value, parse_as="func")

                    choices_request = Request(
                        system=request.system,
                        system_version=request.system_version,
                        instance_name=request.instance_name,
                        command=parsed_value["name"],
                        parameters=map_param_values(parsed_value["args"]),
                    )
                elif isinstance(choices.value, dict):
                    parsed_value = parse(choices.value["command"], parse_as="func")
                    choices_request = Request(
                        system=choices.value.get("system"),
                        system_version=choices.value.get("version"),
                        instance_name=choices.value.get("instance_name", "default"),
                        command=parsed_value["name"],
                        parameters=map_param_values(parsed_value["args"]),
                    )
                else:
                    raise ModelValidationError(
                        "Unable to validate choices for parameter '%s' - Choices value"
                        " must be a string or dictionary " % command_parameter.key
                    )

                response = process_request(
                    choices_request, wait_timeout=self._command_timeout
                )

if self.type == "command" and isinstance(self.value, dict):
            value_keys = self.value.keys()
            for required_key in ("command", "system", "version"):
                if required_key not in value_keys:
                    raise ModelValidationError(
                        f"Can not save choices '{self}': specifying value as a "
                        f"dictionary requires a '{required_key}' item"
                    )

        try:
            if self.details == {}:
                if isinstance(self.value, six.string_types):
                    self.details = parse(self.value)
                elif isinstance(self.value, dict):
                    self.details = parse(self.value["command"])
        except (LarkError, ParseError):
            raise ModelValidationError(
                f"Can not save choices '{self}': Unable to parse"
            )