<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def is_enabled(self, cls):
 """Return whether the given component class is enabled."""

        if cls not in self.enabled:
            self.enabled[cls] = self.is_component_enabled(cls)
        return self.enabled[cls]