Devise\Models\Scaffolding\MigrationScaffolding::buildMigration PHP Method

    private function buildMigration()
    {
        $migrationTemplate = $this->getMigrationTemplatePath();
        $targetFile = $this->getTargetFilePath();
        $template = $this->Framework->File->get($migrationTemplate);
        foreach ($this->constants as $key => $value) {
            $template = str_replace('*|' . $key . '|*', $value, $template);
        }
        $template = $this->convertFields($template);
        return $this->saveMigration($targetFile, $template);
    }