protected function checkUnsupported($xml)
	{
		if (strpos($xml, '<!') !== false)
		{
			throw new InvalidArgumentException('DTDs, CDATA nodes and comments are not allowed');
		}
		if (strpos($xml, '<?') !== false)
		{
			throw new InvalidArgumentException('Processing instructions are not allowed');
		}
	}
protected function checkUnsupported($xml)
	{
		if (strpos($xml, '<!') !== false)
		{
			throw new InvalidArgumentException('DTDs, CDATA nodes and comments are not allowed');
		}
		if (strpos($xml, '<?') !== false)
		{
			throw new InvalidArgumentException('Processing instructions are not allowed');
		}
	}
protected function checkUnsupported ( $ xml ) { if ( strpos ( $ xml , '<!' ) !== false ) { throw new InvalidArgumentException ( 'DTDs, CDATA nodes and comments are not allowed' ) ; } if ( strpos ( $ xml , '<?' ) !== false ) { throw new InvalidArgumentException ( 'Processing instructions are not allowed' ) ; } }
Test for the presence of unsupported XML and throw an exception if found

@param  string $xml XML
@return void
Test for the presence of unsupported XML and throw an exception if found