code: def get_installed_classes(cls):
          
          installed_classes = {}
          for entry_point in pkg_resources.iter_entry_points(cls.entry_point):
              try:
                  plugin = entry_point.load()
              except ImportError as e:
                  logger.error(
                      "Could not load plugin %s: %s", entry_point.name, str(e)
                  )
                  continue
  
              if not issubclass(plugin, cls):
                  logger.error(
                      "Could not load plugin %s:" +
                      " %s class is not subclass of %s",
                      entry_point.name, plugin.__class__.__name__, cls.__name__
                  )
                  continue
  
              if not plugin.validate_dependencies():
                  logger.error(
                      "Could not load plugin %s:" +
                      " %s class dependencies not met",
                      entry_point.name, plugin.__name__
                  )
                  continue
  
              installed_classes[entry_point.name] = plugin
  
          return installed_classes
docs: Iterates over installed plugins associated with the `entry_point` and
          returns a dictionary of viable ones keyed off of their names.
  
          A viable installed plugin is one that is both loadable *and* a subclass
          of the Pluggable subclass in question.