Method "minifyHTML" is not defined in "Potato_Compressor_Model_Observer"

#0 /home/antsq/public_html/app/code/core/Mage/Core/Model/App.php(1360): Mage::throwException('Method "minifyH...')
#1 /home/antsq/public_html/app/code/core/Mage/Core/Model/App.php(1337): Mage_Core_Model_App->_callObserverMethod(Object(Potato_Compressor_Model_Observer), 'minifyHTML', Object(Varien_Event_Observer))
#2 /home/antsq/public_html/app/Mage.php(448): Mage_Core_Model_App->dispatchEvent('controller_fron...', Array)
#3 /home/antsq/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(182): Mage::dispatchEvent('controller_fron...', Array)
#4 /home/antsq/public_html/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#5 /home/antsq/public_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#6 /home/antsq/public_html/index.php(84): Mage::run('', 'store')
#7 {main}