def lst = [1,2,3,4];
def int count = 0
lst.findAll {
    count++
}

groovy.lang.MissingMethodException: No signature of method: Script1.next() is applicable for argument types: () values: []
Possible solutions: wait(), wait(long), getAt(java.lang.String), inject(groovy.lang.Closure), wait(long, int), inject(java.lang.Object, groovy.lang.Closure)
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:58)
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:64)
	at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:54)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
	at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:155)
	at org.kohsuke.groovy.sandbox.GroovyInterceptor.onMethodCall(GroovyInterceptor.java:23)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:123)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:110)
	at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:153)
	at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:157)
	at org.kohsuke.groovy.sandbox.impl.Checker$checkedCall$0.callStatic(Unknown Source)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallStatic(CallSiteArray.java:56)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callStatic(AbstractCallSite.java:194)
	at Script1$_run_closure1.doCall(Script1.groovy:4)

def lst = [1,2,3,4];
def int count = 0
lst.findAll {
    count = count + 1
}