public function mappingsAction()
{
echo "<pre>";
echo "All units\n";
print_r(MappingHelper::allUnits());
echo "<hr>Concepts in unit 4\n";
print_r(MappingHelper::conceptsInUnit("4"));
echo "<hr>Questions in concept (lecture number) 1\n";
print_r(MappingHelper::questionsInConcept("1"));
echo "<hr>Question info for question 78.4\n";
print_r(MappingHelper::questionInformation("78.4"));
echo "<hr>Videos for concept 9\n";
print_r(MappingHelper::videosForConcept("9"));
echo "<hr>Resources for concept 1\n";
print_r(MappingHelper::resourcesForConcept("1"));
echo "<hr>Concepts within the past 2 weeks: \n";
print_r(MappingHelper::conceptsWithin2Weeks());
}
