java.lang.ClassNotFoundException: ["hudson.slaves.RetentionStrategy$Always","hudson.slaves.SimpleScheduledRetentionStrategy","hudson.slaves.RetentionStrategy$Demand"]
	at hudson.PluginManager$UberClassLoader.findClass(PluginManager.java:2154)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
	at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:681)
Caused: java.lang.IllegalArgumentException: Class ["hudson.slaves.RetentionStrategy$Always","hudson.slaves.SimpleScheduledRetentionStrategy","hudson.slaves.RetentionStrategy$Demand"] is specified in JSON, but no such class found in classLoader hudson.PluginManager$UberClassLoader
	at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:686)
Caused: java.lang.IllegalArgumentException: Failed to instantiate class hudson.slaves.RetentionStrategy from {"stapler-class":["hudson.slaves.RetentionStrategy$Always","hudson.slaves.SimpleScheduledRetentionStrategy","hudson.slaves.RetentionStrategy$Demand"]}
	at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:693)
	at org.kohsuke.stapler.RequestImpl.bindJSON(RequestImpl.java:490)
	at org.kohsuke.stapler.RequestImpl.instantiate(RequestImpl.java:799)
Caused: java.lang.IllegalArgumentException: Failed to convert the retentionStrategy parameter of the constructor public org.jenkinci.plugins.mock_slave.MockSlave(java.lang.String,int,hudson.model.Node$Mode,java.lang.String,hudson.slaves.RetentionStrategy,java.util.List) throws java.io.IOException,hudson.model.Descriptor$FormException
	at org.kohsuke.stapler.RequestImpl.instantiate(RequestImpl.java:801)
	at org.kohsuke.stapler.RequestImpl.access$200(RequestImpl.java:85)
	at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:690)
Caused: java.lang.IllegalArgumentException: Failed to instantiate class org.jenkinci.plugins.mock_slave.MockSlave from {"name":"mock","numExecutors":"1","labelString":"","mode":"NORMAL","":"hudson.slaves.RetentionStrategy$Always","retentionStrategy":{"stapler-class":["hudson.slaves.RetentionStrategy$Always","hudson.slaves.SimpleScheduledRetentionStrategy","hudson.slaves.RetentionStrategy$Demand"]},"nodeProperties":{"stapler-class-bag":"true"},"type":"org.jenkinci.plugins.mock_slave.MockSlave","Jenkins-Crumb":"…"}
	at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:693)
	at org.kohsuke.stapler.RequestImpl.bindJSON(RequestImpl.java:490)
	at org.kohsuke.stapler.RequestImpl.bindJSON(RequestImpl.java:486)
	at hudson.model.Descriptor.newInstance(Descriptor.java:606)