fix serialization issue

.groovylintrc.json

@@ -18,6 +18,9 @@
         },
         "NoDef": {
             "enabled": false
+        },
+        "UnnecessaryGetter": {
+            "enabled": false
         }
     }
 }

vars/findVersionFromNexusRepo.groovy

@@ -38,7 +38,7 @@ Map call(Map config = [:], Map queryParams = [:]) {
 
     body = response.content
     assets = readJSON text: body
-    if (assets.items && !assets.items.empty) {
+    if (assets.items && !assets.items.isEmpty()) {
         latest = assets.items.last()
         /* We have to use instanceof here. The value SHOULD be null, but it comes back
             as class rather than null. This is probably a bug in the Pipeline Utilities
@@ -46,7 +46,7 @@ Map call(Map config = [:], Map queryParams = [:]) {
         /* groovylint-disable-next-line Instanceof */
         if (latest.version instanceof net.sf.json.JSONNull && latest.name) {
             echo 'Search result version field was null, looking in name field for a version'
-            match = (latest.name =~ /(?<=-)(\d+\.\d+\.\d+)(?=[\.-].*)/)
+            java.util.regex.Matcher match = (latest.name =~ /(?<=-)(\d+\.\d+\.\d+)(?=[\.-].*)/)
             if (!match) {
                 echo "Match: ${match}"
                 error("Regular expression match failed for latest.name: ${latest.name}")