async def _validate_connections(
        self,
        db: AsyncSession,
        source_connection_id: UUID,
        destination_connection_ids: list[UUID],
        embedding_model_connection_id: UUID,
        current_user: schemas.User,
    ) -> None:
        """Validate the connections.

        Args:
            db (AsyncSession): The database session
            source_connection_id (UUID): The ID of the source connection
            destination_connection_ids (list[UUID]): The IDs of the destination connections
            embedding_model_connection_id (UUID): The ID of the embedding model connection
            current_user (schemas.User): The current user
        """
        # Validate the source connection and that it is a source
        source_connection = await crud.connection.get(
            db, id=source_connection_id, current_user=current_user
        )
        if not source_connection:
            raise NotFoundException("Source connection not found")
        if source_connection.integration_type != IntegrationType.SOURCE:
            raise ValueError("Source connection is not a source")

        # Validate the destination connections and that they are destinations
        for destination_connection_id in destination_connection_ids:
            destination_connection = await crud.connection.get(
                db, id=destination_connection_id, current_user=current_user
            )
            if not destination_connection:
                raise NotFoundException("Destination connection not found")

            if destination_connection.integration_type != IntegrationType.DESTINATION:
                raise ValueError("Destination connection is not a destination")

        # Validate the embedding model connection and that it is an embedding model
        embedding_model_connection = await crud.connection.get(
            db, id=embedding_model_connection_id, current_user=current_user
        )
        if not embedding_model_connection:
            raise NotFoundException("Embedding model connection not found")
        if embedding_model_connection.integration_type != IntegrationType.EMBEDDING_MODEL:
            raise ValueError("Embedding model connection is not an embedding model")
Validate the connections.

        Args:
            db (AsyncSession): The database session
            source_connection_id (UUID): The ID of the source connection
            destination_connection_ids (list[UUID]): The IDs of the destination connections
            embedding_model_connection_id (UUID): The ID of the embedding model connection
            current_user (schemas.User): The current user
        
backend/airweave/crud/crud_sync.py