public function testPipeline_Append()
{
$pipeline = new Pipeline($this->collection);
// insert new match pipeline
$pipeline->match(array('field1' => 'value1'));
// insert new project pipeline
$pipeline->project(array('field2' => 'value2'));
// insert new match pipeline
$pipeline->match(array('field3' => 'value3'));
// append match pipeline to previous
$pipeline->match(array('field3' => 'value3merged', 'field4' => 'value4'));
// insert new sort pipeline
$pipeline->sort(array('field5' => 'value5'));
// insert new group pipeline
$pipeline->group(array('_id' => '$groupField', 'field6' => array('$sum' => 1)));
$this->assertEquals(array(array('$match' => array('field1' => 'value1')), array('$project' => array('field2' => 'value2')), array('$match' => array('field3' => 'value3merged', 'field4' => 'value4')), array('$sort' => array('field5' => 'value5')), array('$group' => array('_id' => '$groupField', 'field6' => array('$sum' => 1)))), $pipeline->toArray());
}