class RuboCop::Cop::ThreadSafety::ClassInstanceVariable

def in_def_class_methods_module?(node)
  defn = node.ancestors.find do |ancestor|
    break if new_lexical_scope?(ancestor)
    ancestor.def_type?
  end
  return false unless defn
  mod = defn.ancestors.find do |ancestor|
    %i[class module].include?(ancestor.type)
  end
  return false unless mod
  class_methods_module?(mod)
end