fix getters

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@chartwerk/core",
-  "version": "0.6.7",
+  "version": "0.6.8",
   "description": "Chartwerk core",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

src/models/series.ts

@@ -98,11 +98,11 @@ export class CoreSeries<T extends Serie> {
   }
 
   get leftYRelatedSeries(): Array<T> {
-    return this.visibleSeries.filter(serie => serie.yOrientation = yAxisOrientation.LEFT);
+    return this.visibleSeries.filter(serie => serie.yOrientation === yAxisOrientation.LEFT);
   }
 
   get rightYRelatedSeries(): Array<T> {
-    return this.visibleSeries.filter(serie => serie.yOrientation = yAxisOrientation.RIGHT);
+    return this.visibleSeries.filter(serie => serie.yOrientation === yAxisOrientation.RIGHT);
   }
 
   get areSeriesForY1Exist(): boolean {