private static MethodsChain createChainFromFirstElement(
     final MethodsChain chain, final PsiClass newQualifierClass) {
   final String qualifiedClassName = newQualifierClass.getQualifiedName();
   if (qualifiedClassName == null) {
     throw new IllegalArgumentException();
   }
   return new MethodsChain(chain.getFirst(), chain.getChainWeight(), qualifiedClassName);
 }