How to use the brewtils.models.Command function in brewtils

created_at = FieldBase(field_type="DATE", default=datetime.datetime.utcnow, required=True)
    updated_at = FieldBase(field_type="DATE", default=None, required=True)
    error_class = FieldBase(field_type="STRING")
    has_parent = FieldBase(field_type="BOOLEAN")
    requester = FieldBase(field_type="STRING")

class System:
    brewtils_model = brewtils.models.System

    name = FieldBase(field_type="STRING", required=True, unique_with=['name','version', 'namespace'])
    description = FieldBase(field_type="STRING")
    version = FieldBase(field_type="STRING", required=True)
    namespace = FieldBase(field_type="STRING", required=True)
    max_instances = FieldBase(field_type="INT", default=1)
    instances = FieldBase(field_type=brewtils.models.Instance, is_ref=True, is_list=True, reverse_delete_rule="PULL")
    commands = FieldBase(field_type=brewtils.models.Command, is_ref=True, is_list=True, reverse_delete_rule="PULL")
    icon_name = FieldBase(field_type="STRING")
    display_name = FieldBase(field_type="STRING")
    metadata = FieldBase(field_type="DICT")
    local = FieldBase(field_type="BOOLEAN", default=True)

class Event:
    brewtils_model = brewtils.models.Event

    name = FieldBase(field_type="STRING", required=True)
    namespace = FieldBase(field_type="STRING", required=True)
    garden = FieldBase(field_type="STRING")
    payload = FieldBase(field_type="DICT")
    error = FieldBase(field_type="BOOLEAN")
    metadata = FieldBase(field_type="DICT")
    timestamp = FieldBase(field_type="DATE")

if not self.nullable and self.optional and self.default is None:
            raise ModelValidationError(
                f"Can not save Parameter {self}: For this Parameter nulls are not "
                f"allowed, but the parameter is optional with no default defined."
            )

        if len(self.parameters) != len(
            set(parameter.key for parameter in self.parameters)
        ):
            raise ModelValidationError(
                f"Can not save Parameter {self}: Contains Parameters with duplicate keys"
            )


class Command(MongoModel, Document):
    brewtils_model = brewtils.models.Command

    name = StringField(required=True, unique_with="system")
    description = StringField()
    parameters = ListField(EmbeddedDocumentField("Parameter"))
    command_type = StringField(choices=BrewtilsCommand.COMMAND_TYPES, default="ACTION")
    output_type = StringField(choices=BrewtilsCommand.OUTPUT_TYPES, default="STRING")
    output_types = ListField()
    output_labels = ListField()
    schema = DictField()
    form = DictField()
    template = StringField()
    hidden = BooleanField()
    icon_name = StringField()
    # reverse_delete_rule=CASCADE is set later, can't set until System is defined
    system = ReferenceField("System")

type_info = FieldBase(field_type="JSON", required=False)
    parameters = FieldBase(
        field_type=brewtils.models.Parameter, default=None, is_list=True
    )


class Command:
    brewtils_model = brewtils.models.Command

    name = FieldBase(field_type="STRING", required=True)
    description = FieldBase(field_type="STRING")
    parameters = FieldBase(
        field_type=brewtils.models.Parameter, default=None, is_list=True
    )
    command_type = FieldBase(
        field_type="STRING", choices=BrewtilsCommand.COMMAND_TYPES, default="ACTION"
    )
    output_type = FieldBase(
        field_type="STRING", choices=BrewtilsCommand.OUTPUT_TYPES, default="STRING"
    )
    schema = FieldBase(field_type="JSON")
    form = FieldBase(field_type="JSON")
    template = FieldBase(field_type="STRING")
    icon_name = FieldBase(field_type="STRING")

    def clean(self):
        """Validate before saving to the database"""

        if not self.name:
            raise ModelValidationError(
                f"Can not save Command"
                f"{' for system ' + self.system.name if self.system else ''}"

def clean(self):
        """Validate before saving to the database"""

        if not self.name:
            raise ModelValidationError(
                f"Can not save Command"
                f"{' for system ' + self.system.name if self.system else ''}"
                f": Missing name"
            )

        if self.command_type not in BrewtilsCommand.COMMAND_TYPES:
            raise ModelValidationError(
                f"Can not save Command {self}: Invalid command type '{self.command_type}'"
            )

        if self.output_type not in BrewtilsCommand.OUTPUT_TYPES:
            raise ModelValidationError(
                f"Can not save Command {self}: Invalid output type '{self.output_type}'"
            )

        if len(self.parameters) != len(
                set(parameter.key for parameter in self.parameters)
        ):
            raise ModelValidationError(
                f"Can not save Command {self}: Contains Parameters with duplicate keys"
            )

#from beer_garden.db.sql.util import check_indexes, ensure_roles, ensure_users

logger = logging.getLogger(__name__)

ModelType = Union[
    Type[brewtils.models.Command],
    Type[brewtils.models.Instance],
    Type[brewtils.models.Job],
    Type[brewtils.models.Request],
    Type[brewtils.models.RequestTemplate],
    Type[brewtils.models.System],
    Type[brewtils.models.Garden],
]

ModelItem = Union[
    brewtils.models.Command,
    brewtils.models.Instance,
    brewtils.models.Job,
    brewtils.models.Request,
    brewtils.models.RequestTemplate,
    brewtils.models.System,
    brewtils.models.Garden,
]

_model_map = beer_garden.db.sql.models.schema_mapping

engine = None
Session = None


def from_brewtils(obj: ModelItem) -> SqlModel:
    """Convert an item from its Brewtils model to its  one

"output_labels": {"field": ListField, "kwargs": {}},
    }

    for field_name, field_info in TEMPLATE_FIELDS.items():
        locals()[field_name] = field_info["field"](**field_info["kwargs"])

    parent = ReferenceField(
        "Request", dbref=True, required=False, reverse_delete_rule=CASCADE
    )
    children = DummyField(required=False)
    output = StringField()
    output_type = StringField(choices=BrewtilsCommand.OUTPUT_TYPES)
    output_types = ListField()
    output_labels = ListField()
    status = StringField(choices=BrewtilsRequest.STATUS_LIST, default="CREATED")
    command_type = StringField(choices=BrewtilsCommand.COMMAND_TYPES)
    created_at = DateTimeField(default=datetime.datetime.utcnow, required=True)
    updated_at = DateTimeField(default=None, required=True)
    error_class = StringField(required=False)
    has_parent = BooleanField(required=False)
    requester = StringField(required=False)

    meta = {
        "auto_create_index": False,  # We need to manage this ourselves
        "index_background": True,
        "indexes": [
            # These are used for sorting all requests
            {"name": "command_index", "fields": ["command"]},
            {"name": "command_type_index", "fields": ["command_type"]},
            {"name": "system_index", "fields": ["system"]},
            {"name": "instance_name_index", "fields": ["instance_name"]},
            {"name": "status_index", "fields": ["status"]},

command_type = FieldBase(field_type="STRING")
    parameters = FieldBase(field_type="DICT")
    comment = FieldBase(field_type="STRING")
    metadata = FieldBase(field_type="DICT")
    output_type = FieldBase(field_type="STRING")


class Request(RequestTemplate):
    brewtils_model = brewtils.models.Request

    parent = FieldBase(field_type=brewtils.models.Request, is_ref=True, reverse_delete_rule="CASCADE")
    children = FieldBase(field_type="PLACE_HOLDER")
    output = FieldBase(field_type="STRING")
    output_type = FieldBase(field_type="STRING", choices=BrewtilsCommand.OUTPUT_TYPES)
    status = FieldBase(field_type="STRING", choices=BrewtilsRequest.STATUS_LIST, default="CREATED")
    command_type = FieldBase(field_type="STRING", choices=BrewtilsCommand.COMMAND_TYPES)
    created_at = FieldBase(field_type="DATE", default=datetime.datetime.utcnow, required=True)
    updated_at = FieldBase(field_type="DATE", default=None, required=True)
    error_class = FieldBase(field_type="STRING")
    has_parent = FieldBase(field_type="BOOLEAN")
    requester = FieldBase(field_type="STRING")

class System:
    brewtils_model = brewtils.models.System

    name = FieldBase(field_type="STRING", required=True, unique_with=['name','version', 'namespace'])
    description = FieldBase(field_type="STRING")
    version = FieldBase(field_type="STRING", required=True)
    namespace = FieldBase(field_type="STRING", required=True)
    max_instances = FieldBase(field_type="INT", default=1)
    instances = FieldBase(field_type=brewtils.models.Instance, is_ref=True, is_list=True, reverse_delete_rule="PULL")
    commands = FieldBase(field_type=brewtils.models.Command, is_ref=True, is_list=True, reverse_delete_rule="PULL")

choices = FieldBase(field_type=brewtils.models.Choices, default=None)
    nullable = FieldBase(field_type="BOOLEAN", required=False, default=False)
    maximum = FieldBase(field_type="INT", required=False)
    minimum = FieldBase(field_type="INT", required=False)
    regex = FieldBase(field_type="STRING", required=False)
    form_input_type = FieldBase(
        field_type="STRING", required=False, choices=BrewtilsParameter.FORM_INPUT_TYPES
    )
    type_info = FieldBase(field_type="JSON", required=False)
    parameters = FieldBase(
        field_type=brewtils.models.Parameter, default=None, is_list=True
    )


class Command:
    brewtils_model = brewtils.models.Command

    name = FieldBase(field_type="STRING", required=True)
    description = FieldBase(field_type="STRING")
    parameters = FieldBase(
        field_type=brewtils.models.Parameter, default=None, is_list=True
    )
    command_type = FieldBase(
        field_type="STRING", choices=BrewtilsCommand.COMMAND_TYPES, default="ACTION"
    )
    output_type = FieldBase(
        field_type="STRING", choices=BrewtilsCommand.OUTPUT_TYPES, default="STRING"
    )
    schema = FieldBase(field_type="JSON")
    form = FieldBase(field_type="JSON")
    template = FieldBase(field_type="STRING")
    icon_name = FieldBase(field_type="STRING")

)


class System(Base):
    id = Column(sqlalchemy.Integer, primary_key=True)
    __tablename__ = brewtils.models.System.schema


class Instance(Base):
    id = Column(sqlalchemy.Integer, primary_key=True)
    __tablename__ = brewtils.models.Instance.schema


class Command(Base):
    id = Column(sqlalchemy.Integer, primary_key=True)
    __tablename__ = brewtils.models.Command.schema


class Parameter(Base):
    id = Column(sqlalchemy.Integer, primary_key=True)
    __tablename__ = brewtils.models.Parameter.schema


class Request(Base):
    id = Column(sqlalchemy.Integer, primary_key=True)
    __tablename__ = brewtils.models.Request.schema


class Choices(Base):
    id = Column(sqlalchemy.Integer, primary_key=True)
    __tablename__ = brewtils.models.Choices.schema

namespace = FieldBase(field_type="STRING", required=True)
    command = FieldBase(field_type="STRING", required=True)
    command_type = FieldBase(field_type="STRING")
    parameters = FieldBase(field_type="DICT")
    comment = FieldBase(field_type="STRING")
    metadata = FieldBase(field_type="DICT")
    output_type = FieldBase(field_type="STRING")


class Request(RequestTemplate):
    brewtils_model = brewtils.models.Request

    parent = FieldBase(field_type=brewtils.models.Request, is_ref=True, reverse_delete_rule="CASCADE")
    children = FieldBase(field_type="PLACE_HOLDER")
    output = FieldBase(field_type="STRING")
    output_type = FieldBase(field_type="STRING", choices=BrewtilsCommand.OUTPUT_TYPES)
    status = FieldBase(field_type="STRING", choices=BrewtilsRequest.STATUS_LIST, default="CREATED")
    command_type = FieldBase(field_type="STRING", choices=BrewtilsCommand.COMMAND_TYPES)
    created_at = FieldBase(field_type="DATE", default=datetime.datetime.utcnow, required=True)
    updated_at = FieldBase(field_type="DATE", default=None, required=True)
    error_class = FieldBase(field_type="STRING")
    has_parent = FieldBase(field_type="BOOLEAN")
    requester = FieldBase(field_type="STRING")

class System:
    brewtils_model = brewtils.models.System

    name = FieldBase(field_type="STRING", required=True, unique_with=['name','version', 'namespace'])
    description = FieldBase(field_type="STRING")
    version = FieldBase(field_type="STRING", required=True)
    namespace = FieldBase(field_type="STRING", required=True)
    max_instances = FieldBase(field_type="INT", default=1)