Method "addJqueryLibrary" is not defined in "Magentothem_Upsellslider_Model_Layout_Generate_Observer"

#0 /home/sitbette/public_html/app/code/core/Mage/Core/Model/App.php(1340): Mage::throwException('Method "addJque...')
#1 /home/sitbette/public_html/app/code/core/Mage/Core/Model/App.php(1317): Mage_Core_Model_App->_callObserverMethod(Object(Magentothem_Upsellslider_Model_Layout_Generate_Observer), 'addJqueryLibrar...', Object(Varien_Event_Observer))
#2 /home/sitbette/public_html/app/Mage.php(448): Mage_Core_Model_App->dispatchEvent('controller_acti...', Array)
#3 /home/sitbette/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(351): Mage::dispatchEvent('controller_acti...', Array)
#4 /home/sitbette/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(269): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#5 /home/sitbette/public_html/app/code/local/Magentothem/Layerednavigationajax/controllers/ResultController.php(121): Mage_Core_Controller_Varien_Action->loadLayout()
#6 /home/sitbette/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Magentothem_Layerednavigationajax_ResultController->indexAction()
#7 /home/sitbette/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(250): Mage_Core_Controller_Varien_Action->dispatch('index')
#8 /home/sitbette/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#9 /home/sitbette/public_html/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#10 /home/sitbette/public_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#11 /home/sitbette/public_html/index.php(87): Mage::run('', 'store')
#12 {main}