Importing (and creating) data for more than one table

public static function getColumns(): array
    {
        return [
            ImportColumn::make('first_name')
                ->label('First Name')
                ->requiredMapping()
                ->rules(['required', 'string'])
                ->examples(['John', 'Jane'])
                ->exampleHeader('First Name'),

            ImportColumn::make('last_name')
                ->label('Last Name')
                ->requiredMapping()
                ->rules(['required', 'string'])
                ->examples(['Doe', 'Mathews'])
                ->exampleHeader('Last Name'),

            ImportColumn::make('email')
                ->label('Email Address')
                ->requiredMapping()
                ->rules(['required', 'email'])
                ->examples(['john@gmail.com', 'mathews@yahoo.com'])
                ->exampleHeader('Email Address'),
        ];
    }

public function resolveRecord(): ?User
    {
        return User::firstOrNew(['email' => $this->data['email']]);
    }

  protected function afterSave(): void
    {
        if (!$this->record->teacher) {
            Teacher::create(['user_id' => $this->record->id]);
        }
    }