Wrap all already existing methods

[panagulis72]

Hi,
I'm going to add the nativescript-https to my Nativescript/Angular app. I already have a very large number of API calls created using HTTPClient Module.
So, for example, my API calls are so structured:

   firstApiCall() {
                 let httpParams = new HttpParams();
                  ...adding parameters...
        return this.http.get<number>(`my_url`, {
            params: httpParams
        })
            .pipe(
                map((data) => {
                    return data
                })
            );
    }

    secondApiCall(data) {
        return this.http.post<boolean>('my_second_url', {
            data: data
        })
            .pipe(
                map((res) => {
                    return res;
                })
            );
    }

with interceptor:

       import { HttpEvent, HttpHandler, HttpHeaders, HttpInterceptor, HttpRequest } from       
   "@angular/common/http";
          import { Injectable } from '@angular/core';
          import { Observable } from 'rxjs';
          @Injectable()
          export class AuthInterceptor implements HttpInterceptor {
          constructor() {
          }
          intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const headerSettings: { [name: string]: string | string[]; } = {};

        for (const key of req.headers.keys()) {
            headerSettings[key] = req.headers.getAll(key);
        }
            headerSettings['Authorization'] = 'Bearer .....................';
        if (!(req.body instanceof FormData)) {
            headerSettings['Content-Type'] = 'application/json';
        }
        const newHeader = new HttpHeaders(headerSettings);

        const changedReq = req.clone({
            headers: newHeader
        });
        return next.handle(changedReq);
     }
     }

To avoid manually changing each call (which would take an infinite amount of time) is there a way to create a wrapper?