Bagaimana menggunakan tipe data varchar pada InstallSchema Magento 2?

namespace Tutorial\SimpleNews\Setup;

use Magento\Framework\Setup\InstallSchemaInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\SchemaSetupInterface;
use Magento\Framework\DB\Ddl\Table;

class InstallSchema implements InstallSchemaInterface
{

public function install(SchemaSetupInterface $setup, ModuleContextInterface $context)
{
$installer = $setup;
$installer->startSetup();

// Get tutorial_simplenews table
$tableName = $installer->getTable('new_table');
// Check if the table already exists
if ($installer->getConnection()->isTableExists($tableName) != true) {
// Create tutorial_simplenews table
$table = $installer->getConnection()
->newTable($tableName)
->addColumn(
'id', Table::TYPE_INTEGER, null, [
'identity' => true,
'unsigned' => true,
'nullable' => false,
'primary' => true
], 'ID'
)
->addColumn(
'description', Table::TYPE_TEXT, null, ['nullable' => false, 'default' => ''], 'Description'
)
->setOption('type', 'InnoDB')
->setOption('charset', 'utf8');
$installer->getConnection()->createTable($table);
}
$installer->endSetup();
}

}

->addColumn('description', Table::TYPE_TEXT, null, ['nullable' => false, 'default' => ''], Description')

const TYPE_BOOLEAN = 'boolean';

const TYPE_SMALLINT = 'smallint';

const TYPE_INTEGER = 'integer';

const TYPE_BIGINT = 'bigint';

const TYPE_FLOAT = 'float';

const TYPE_NUMERIC = 'numeric';

const TYPE_DECIMAL = 'decimal';

const TYPE_DATE = 'date';

const TYPE_TIMESTAMP = 'timestamp';

// Capable to support date-time from 1970 + auto-triggers in some RDBMS
const TYPE_DATETIME = 'datetime';

// Capable to support long date-time before 1970
const TYPE_TEXT = 'text';

const TYPE_BLOB = 'blob';

// Used for back compatibility, when query param can't use statement options
const TYPE_VARBINARY = 'varbinary';

->addColumn('description', Table::TYPE_TEXT, null, ['nullable' => false, 'default' => ''], Description') //text

->addColumn('description', Table::TYPE_TEXT, 10, ['nullable' => false, 'default' => ''], Description') // varchar(10)