<?php

namespace duxet\RethinkDB\Schema;

use Illuminate\Database\Schema\Grammars\Grammar as BaseGrammar;

/**
 * Class Grammar
 *
 * @package Moloquent\Schema
 */
class Grammar extends BaseGrammar {
}

Fix issue supportsSchemaTransactions() on null
Fix issue supportsSchemaTransactions() on null

got this issue while fixing existing issue fix this issue 
Call to a member function supportsSchemaTransactions() on null
by adding Grammar.php and editing Connection.php