let reqHeaders = new Headers({ 'Content-Type': undefined});
        reqHeaders.append('Accept', 'application/vnd.emc.documentum+json');
        //setting username
        let username = "<username>";
        //setting password

        let password = "<password>";
        //creating converting to binary
        let authToken = btoa(username + ":" +password);
        //setting up the Authorization
        reqHeaders.append('Authorization', 'Basic ' + authToken);

        //-Creating the format in the documentum way for the metadata.

        var docObj = this.buildPersistentObject(['r_object_type', 'dm_document', 'object_name', "test.pdf"])

        //enter code here`Forming Multipart/Form  -->

           var fd = new FormData();
           fd.append('data', new Blob([JSON.parse(JSON.stringify(docObj))], {type: 'application/vnd.emc.documentum+json'}));
           fd.append('content', file);

        <!-- Sending the Post Request -->

        return this._http.post("http://localhost:8080/dctm-rest/repositories/demo/folders/0b01e24080008993/documents", fd, { headers: reqHeaders });

        <!-- Below is the error i am getting when i post the request. But i have not set application/octet-stream  sending only

         {"status":415,"code":"E_UNSUPPORTED_MEDIA_TYPE","message":"The specified media type application/octet-stream is not supported. Supported media types: [application/vnd.emc.documentum+json, application/vnd.emc.documentum+xml].","details":"Content type 'application/octet-stream' not supported","id":"adcf72a5-f43e-4fa6-8cee-54db707122d2"}

<!-- Creating Mulitpart Message -->
          var fd = new FormData()
        <!-- appending the metadata -->
        fd.append('metadata', new Blob([angular.toJson(data)], {type: dctmConstants.MIME.VND_DCTM_JSON}))
        <!-- appending the content -->
        fd.append('content', file)
        <!-- setting the content type to undefined -->
        headers[dctmConstants.HEADERS.CONTENT_TYPE] = undefined;

       // How this can be converted to angular 5

        headers['transformRequest'] = angular.identity;
        data = fd

        <!-- Post Request call -->

        return this.http({method: 'POST',url: "http://localhost:8080/dctm-rest/repositories/demo/folders/0b01e24080008993/documents",headers: headers,data: data})