attempting to call the supporting function correctly

vars/podTemplates.groovy

@@ -6,7 +6,7 @@ def podLabel() {
 }
 
 // return kubernetes pod defination
-def podYaml(def requiredContainers){
+def podYaml(Map requiredContainers){
     def dockerRepo = "registry.c.test-chamber-13.lan"
     def output = """
 ---
@@ -17,7 +17,7 @@ metadata:
 spec:
   containers:
 """
-    if (requiredContainers['kaniko'] == true) {
+    if (requiredContainers.kaniko] == true) {
         output += """
   - name: kaniko
     imagePullPolicy: Always
@@ -27,7 +27,7 @@ spec:
     - /busybox/sh
 """
     }
-    if (requiredContainer['alpine'] == true) {
+    if (requiredContainer.alpine == true) {
         output += """
   - name: alpine
     imagePullPolicy: Always