docs: def isdir(self, relpath, rsc=None):
          """
          Returns whether or not the resource is a directory.
          
          :return     <bool>
          """
          filepath = self.find(relpath, rsc)
          if filepath.startswith(':'):
              resource = QtCore.QResource(filepath)
              return not resource.isFile()
          else:
              return os.path.isdir(filepath)