[2244] added comment about has_comonent as it may not be very obvious.

src/lib/python/isc/bind10/component.py

@@ -573,6 +573,9 @@ class Configurator:
 
     def has_component(self, component):
         '''Return if a specified component is configured.'''
+        # Values of self._components are tuples of (name, component).
+        # Extract the components of the tuples and see if the given one
+        # is included.
         return component in map(lambda x: x[1], self._components.values())
 
     def reconfigure(self, configuration):