public function close(?string $connection = null): void
	{
		$connection = $connection ?? $this->default;

		if(isset($this->connections[$connection]))
		{
			if(method_exists($this->connections[$connection], 'close'))
			{
				// Call close on the connection object in case there's a reference
				// to the connection that won't be garbage collected immediately

				$this->connections[$connection]->close();
			}

			unset($this->connections[$connection]);
		}
	}