[2244] added a simple has_component() method to configurtor.

should be pretty trivial, so added a couple of test cases as part of
other tests.

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

@@ -571,6 +571,10 @@ class Configurator:
         self._running = False
         self.__reconfigure_internal(self._components, {})
 
+    def has_component(self, component):
+        '''Return if a specified component is configured.'''
+        return component in map(lambda x: x[1], self._components.values())
+
     def reconfigure(self, configuration):
         """
         Changes configuration from the current one to the provided. It

src/lib/python/isc/bind10/tests/component_test.py

@@ -896,7 +896,7 @@ class ConfiguratorTest(BossUtils, unittest.TestCase):
         # We run the plan so the component is wired into internal structures
         configurator._run_plan(plan)
         # We should have the 'additional' component in the configurator.
-        self.assertTrue('additional' in configurator._components)
+        self.assertTrue(configurator.has_component(component))
         for count in [0, 1]:    # repeat two times, see below
             self.log = []
             plan = configurator._build_plan(self.__build_components(bigger),
@@ -915,6 +915,8 @@ class ConfiguratorTest(BossUtils, unittest.TestCase):
                 component.failed(0)
         # Run the plan, confirm the specified component is gone.
         configurator._run_plan(plan)
+        self.assertFalse(configurator.has_component(component))
+        # There shouldn't be any other object that has the same name
         self.assertFalse('additional' in configurator._components)
 
         # We want to switch a component. So, prepare the configurator so it