PUYUP

import { Injectable } from '@angular/core';
import {
    HttpRequest,
    HttpHandler,
    HttpEvent,
    HttpInterceptor
} from '@angular/common/http';
import { Observable, BehaviorSubject } from 'rxjs';
import { filter, take, switchMap } from 'rxjs/operators';
import { SigninModuleState } from '../../signin/store/models/signin.model';

PUYUP

class DjangoModel(models.Model):

    @classmethod
    def from_db(cls, db, field_names, values):
        instance = super().from_db(db, field_names, values)
        instance._state.adding = False
        instance._state.db = db
        instance._old_values = dict(zip(field_names, values))
        return instance