code: protected function buildMessage() {
          $className = $this->getClassName();
          $methodName = $this->getMethodName();
          $functionName = $this->getFunctionName();
  
          if ($className !== null && $methodName !== null) {
              $callable = $className . '::' . $methodName;;
          } else {
              $callable = $functionName;
          }
  
          $this->message = s(
              'Container could not resolve argument %s for %s.',
              $this->getArgumentIndex(),
              $callable
          );
      }
docs: Build exception message.