fix(fix the absence of circular structure treatment): fix the lack of…

… circular structure treatment

The Step class uses JSON.stringify without the callback function to handle circular structures. When
passing an object with a circular structure it shows the error "TypeError: Converting circular
structure to JSON" and interrupts code execution. Now, the Step class performs the packaging of
objects with circular structures.

#46

src/step.js

@@ -72,7 +72,7 @@ class Step {
         }
 
         let circularStructureCache = []
-        const _circularStructureHandling = (key, value) => {
+        const _circularStructureHandling = (_, value) => {
             if (typeof value === 'object' && value !== null) {
                 if (circularStructureCache.includes(value)) return
                 circularStructureCache.push(value)