FE7 E77E7member?7E7appendE7Circular dependency detected: E7 => 7 E7to_sE77E7prefixE77E7TOPE7RakeE7 LinkedListE7InvocationChainE7 invocationE7headE7==E7tailE7 RuntimeErrorE7failE7conjE7chainE7EmptyLinkedListE7EmptyInvocationChainE7@parentE7objE7core#define_methodE7EMPTYE7core#define_singleton_methodE7privateE7new)5+7Q)5Ld )AYr.^y