Spock throwing a NoSuchMethodError when contrast a slight that throws an exception

I'm perplexing to exam a groovy slight that throws an difference
controlling Spock. Actually this slight already had a flitting exam before
though we only recently total a throws difference to a slight construction
now. Now spock is observant that there is no such method.This is how my
slight looks like:public def generateFoo(List files) throws FooException {
// code}This is how my exam looks like:given: def record = new
GrailsMockMultipartFile("My File",
getClass().getResourceAsStream("resources/file_size_20b.txt")) def files
= [] files.add(file)when: def retVal = generateFoo(files) then: retVal
instanceof java.util.ArrayListBut when we run a tests it gives me this
error:java.lang.NoSuchMethodError:
generateFaxPreviews(Ljava/util/List;)Ljava/lang/Object;