I recently updated to angular 16 from V15, After change the observable which we declared doesn’t contain/returning the propertly ‘_isScalar’ which is worked before

"rxjs": "~7.5.5",
"tslib": "^2.3.0",
"@angular/core": "^16.2.12",

this is the observable
rowData = new Observable<any[]>();
we are checking this _isScalar like below

if (this.rowData._isScalar !== false) {
//some code
}

This was perfectly working fine in angular 15 after updated to 16 application showing compilation error like below

 error TS2339: Property '_isScalar' does not exist on type 'Observable<any[]>'

259 if (this.rowData._isScalar !== false) {
~~~~~~~
I need a help here why the observable not returning _isScalar propertly or do i need to change the declaration part