Multiple Instances of a Snippet on the same page = FAILS IN REVO. ???

<?php
/*------------------------------------------------------------------------------
INPUT:
	type (str) -- for the type column in the database, e.g. job, job_centers
	tpl (str) -- name of Chunk used for formatting the output of the Categories
		Placeholders: category_id, parent_id, type, name, description, sort
OUTPUT:
	maybe something intended for inclusion in a <select> option in a form

  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
------------------------------------------------------------------------------*/

include_once(MODX_CORE_PATH.'config/edfconfig.inc.php');

if (empty($tpl) || empty($type))
{
	$modx->log(modX::LOG_LEVEL_ERROR, "MISSING ARGS: getCategories Snippet requires &tpl and &type arguments.");
	return '<!-- missing arguments -->';
}

$output = '';

$my_xpdo= new xPDO('mysql:host='.EDF_DB::$host.';dbname='.EDF_DB::$dbname, EDF_DB::$dbuser, EDF_DB::$dbpasswd,'');
$my_xpdo->addPackage(EDF_DB::$package_name,EDF_DB::$package_path);


/* http://rtfm.modx.com//display/xPDO20/Retrieving+Objects */
$query = $my_xpdo->newQuery('Categories');
$query->where(array(  
    'type' => $type,
));

$query->sortby('sort','ASC');
$resources = $my_xpdo->getCollection('Categories', $query );

// Stack the formatted output
foreach ($resources as $r) {  
    $resourceArray = $r->toArray();  
    $resourceArray['cls'] = $rowCls;  
    $output .= $modx->getChunk($tpl,$resourceArray);  
}

unset($tpl);
unset($type);
unset($my_xpdo);
$modx->log(modX::LOG_LEVEL_ERROR, "getCategories Snippet ran: $output");
return $output;
?>

Fatal error: Cannot redeclare class

// Instantiate and store an instance of xPDO the first time the Snippet is called on a page
if ( !isset($modx->placeholders['edf_xpdo']) || !is_a( $modx->placeholders['edf_xpdo'], 'xPDO') )
{
	$modx->placeholders['my_xpdo']= new xPDO('mysql:host='.EDF_DB::$host.';dbname='.EDF_DB::$dbname, EDF_DB::$dbuser, EDF_DB::$dbpasswd,'');
	$modx->placeholders['my_xpdo']->addPackage(EDF_DB::$package_name,EDF_DB::$package_path);
}

require_once 'path/to/MyClassName.class.php';

// send the class instance to a modx placeholder if it hasn't been called already
if ( !isset($modx->placeholders['MyClassName']) )
{
    $modx->placeholders['MyClassName']= new MyClassName;
}
// shorten the variable name, for convenience
$myClass = $modx->placeholders['MyClassName'];

$output = $myClass->myMethodName($parameters);
$output .= $myClass->myOtherMethodName($parameters);
return $output;