safeloader: make the base module name and class explit

When looking for tests, the base class and the module where it
comes from, is of uttermost importance.  But, they have so far
been implicitly defined.

Let's make them explicit, which makes improves readability and
will help to make the utility functions reusable.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

avocado/core/safeloader.py

@@ -340,7 +340,7 @@ def get_methods_info(statement_body, class_tags):
     return methods_info
 
 
-def _examine_class(path, class_name, is_avocado):
+def _examine_class(path, class_name, is_avocado, target_module, target_class):
     """
     Examine a class from a given path
 
@@ -351,12 +351,17 @@ def _examine_class(path, class_name, is_avocado):
     :param is_avocado: whether the inheritance from 'avocado.Test' has
                        been determined or not
     :type is_avocado: bool
+    :param target_module: the module name under which the target_class lives
+    :type target_module: str
+    :param target_class: the name of the class that class_name should
+                         ultimatetly inherit from
+    :type target_class: str
     :returns: tuple where first item is a list of test methods detected
               for given class; second item is set of class names which
               look like avocado tests but are force-disabled.
     :rtype: tuple
     """
-    module = PythonModule(path)
+    module = PythonModule(path, target_module, target_class)
     info = []
     disabled = []
 
@@ -398,7 +403,8 @@ def _examine_class(path, class_name, is_avocado):
                 continue
             parent_class = parent.id
             _info, _disabled, _avocado = _examine_class(module.path, parent_class,
-                                                        is_avocado)
+                                                        is_avocado, target_module,
+                                                        target_class)
             if _info:
                 parents.remove(parent)
                 info.extend(_info)
@@ -442,7 +448,9 @@ def _examine_class(path, class_name, is_avocado):
                                                 modules_paths)
             _info, _dis, _avocado = _examine_class(found_ppath,
                                                    parent_class,
-                                                   is_avocado)
+                                                   is_avocado,
+                                                   target_module,
+                                                   target_class)
             if _info:
                 info.extend(_info)
                 _disabled.update(_dis)
@@ -464,7 +472,10 @@ def find_avocado_tests(path):
               force-disabled.
     :rtype: tuple
     """
-    module = PythonModule(path)
+    module_name = 'avocado'
+    class_name = 'Test'
+
+    module = PythonModule(path, module_name, class_name)
     # The resulting test classes
     result = collections.OrderedDict()
     disabled = set()
@@ -508,7 +519,8 @@ def find_avocado_tests(path):
                 continue
             parent_class = parent.id
             _info, _dis, _avocado = _examine_class(module.path, parent_class,
-                                                   is_avocado)
+                                                   is_avocado, module_name,
+                                                   class_name)
             if _info:
                 parents.remove(parent)
                 info.extend(_info)
@@ -551,7 +563,9 @@ def find_avocado_tests(path):
             _, found_ppath, _ = imp.find_module(parent_module, modules_paths)
             _info, _dis, _avocado = _examine_class(found_ppath,
                                                    parent_class,
-                                                   is_avocado)
+                                                   is_avocado,
+                                                   module_name,
+                                                   class_name)
             if _info:
                 info.extend(_info)
                 _disabled.update(_dis)