jira listener - ambiguous method

[pmauduit]

17:33:30.204 [Grizzly(2)] ERROR com.ullink.slack.simpleslackapi.impl.SlackWebSocketSessionImpl - caught exception in dispatchImpl
groovy.lang.GroovyRuntimeException: Ambiguous method overloading for method com.ullink.slack.simpleslackapi.impl.SlackWebSocketSessionImpl#sendMessage.
Cannot resolve which method to invoke for [null, class com.ullink.slack.simpleslackapi.SlackPreparedMessage] due to overlapping prototypes between:
	[class com.ullink.slack.simpleslackapi.SlackChannel, class com.ullink.slack.simpleslackapi.SlackPreparedMessage]
	[class java.lang.String, class com.ullink.slack.simpleslackapi.SlackPreparedMessage]
	at groovy.lang.MetaClassImpl.doChooseMostSpecificParams(MetaClassImpl.java:3385)
	at groovy.lang.MetaClassImpl.chooseMostSpecificParams(MetaClassImpl.java:3361)
	at groovy.lang.MetaClassImpl.chooseMethodInternal(MetaClassImpl.java:3351)
	at groovy.lang.MetaClassImpl.chooseMethod(MetaClassImpl.java:3295)
	at groovy.lang.MetaClassImpl.getNormalMethodWithCaching(MetaClassImpl.java:1460)
	at groovy.lang.MetaClassImpl.getMethodWithCaching(MetaClassImpl.java:1376)
	at org.codehaus.groovy.vmplugin.v8.Selector$MethodSelector.chooseMeta(Selector.java:604)
	at org.codehaus.groovy.vmplugin.v8.Selector$MethodSelector.setCallSiteTarget(Selector.java:1010)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface.fallback(IndyInterface.java:351)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface.access$000(IndyInterface.java:49)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface$FallbackSupplier.get(IndyInterface.java:281)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface.lambda$fromCache$1(IndyInterface.java:301)
	at org.apache.groovy.util.concurrent.concurrentlinkedhashmap.ConcurrentLinkedHashMap.lambda$compute$0(ConcurrentLinkedHashMap.java:788)
	at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1705)
	at org.apache.groovy.util.concurrent.concurrentlinkedhashmap.ConcurrentLinkedHashMap.compute(ConcurrentLinkedHashMap.java:800)
	at org.apache.groovy.util.concurrent.concurrentlinkedhashmap.ConcurrentLinkedHashMap.computeIfAbsent(ConcurrentLinkedHashMap.java:777)
	at org.codehaus.groovy.runtime.memoize.LRUCache.getAndPut(LRUCache.java:63)
	at org.codehaus.groovy.vmplugin.v8.CacheableCallSite.getAndPut(CacheableCallSite.java:48)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface.lambda$fromCache$2(IndyInterface.java:298)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface.doWithCallSite(IndyInterface.java:367)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface.fromCache(IndyInterface.java:295)
	at fr.spironet.slackbot.listeners.JiraListener.doOnEvent(JiraListener.groovy:291)
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