title: ERROR TypeError: Converting circular structure to JSON
body: <p>I am working with Angular5.
  I have implemented the following code to send data as json to api, please see below</p>
  
  <p>in xxxx.component.ts</p>
  
  <pre><code>submitProfileData() {
             let registrationsData = [];
             for (let i = 0; i &lt; this.profileModel.registrationData.length; i++ ) {
              registrationsData.push(
                  {
                      id: this.profileModel.registrationData[i].id,
                      registration_number: this.profileModel.registrationData[i].regNo
                  });
             }
             const primary_details = {
              street_line1: this.profileEditForm.controls.streetLine1.get('line1').value,
              street_line2: this.profileEditForm.controls.streetLine2.get('line2').value,
              country: this.profileEditForm.controls.countryName.get('country').value,
              state: this.profileEditForm.controls.stateName.get('state').value,
              };
             const profile_details = {
              name: this.profileEditForm.controls.branchName.get('name').value,
              tradingname: this.profileEditForm.controls.tradingName.get('trname').value,
              acronym: this.profileModel.acronym,
              timezone: this.profileEditForm.controls.timeZone,
              registrations: registrationsData
              };
              this.profileEditService
              .editProfileData({primary_details: primary_details, profile_details: profile_details}, this.branchId)
              .subscribe(suc =&gt; console.log('response', suc));
  
      }
  </code></pre>
  
  <p>in xxxxx.service.ts</p>
  
  <pre><code>editProfileData(data, branchId) {
          console.log('request data', data);
          return this.http.post(this.config.STORE_KEY + '/public/api/business/changerequest/' + 
                   this.userDetails.roleid + '/' + branchId, data)
                   .map((response: Response) =&gt; response.json())
                   .catch(this.handleError);
      }
  </code></pre>
  
  <p>41 line console is printing on chrome console. but i am getting the following error</p>
  
  <pre><code>ERROR TypeError: Converting circular structure to JSON
      at Object.stringify (&lt;anonymous&gt;)
      at Request.webpackJsonp.../../../http/@angular/http.es5.js.Body.text (http.es5.js:839)
      at Request.webpackJsonp.../../../http/@angular/http.es5.js.Request.getBody (http.es5.js:1748)
      at Observable._subscribe (http.es5.js:1275)
      at Observable.webpackJsonp.../../../../rxjs/Observable.js.Observable._trySubscribe (Observable.js:172)
      at Observable.webpackJsonp.../../../../rxjs/Observable.js.Observable.subscribe (Observable.js:160)
      at CatchOperator.webpackJsonp.../../../../rxjs/operators/catchError.js.CatchOperator.call (catchError.js:79)
      at Observable.webpackJsonp.../../../../rxjs/Observable.js.Observable.subscribe (Observable.js:157)
      at MapOperator.webpackJsonp.../../../../rxjs/operators/map.js.MapOperator.call (map.js:56)
      at Observable.webpackJsonp.../../../../rxjs/Observable.js.Observable.subscribe (Observable.js:157)  
  </code></pre>