fix: ScannerImpl - possibleSimpleKeys must be LinkedHashMap
diff --git a/src/main/java/org/yaml/snakeyaml/scanner/ScannerImpl.java b/src/main/java/org/yaml/snakeyaml/scanner/ScannerImpl.java
index 22632ab..687ea2f 100644
--- a/src/main/java/org/yaml/snakeyaml/scanner/ScannerImpl.java
+++ b/src/main/java/org/yaml/snakeyaml/scanner/ScannerImpl.java
@@ -519,7 +519,7 @@
         // Reset simple keys.
         removePossibleSimpleKey();
         this.allowSimpleKey = false;
-        this.possibleSimpleKeys = new HashMap<Integer, SimpleKey>();
+        this.possibleSimpleKeys.clear();
 
         // Read the token.
         Mark mark = reader.getMark();