[extractor] Use classmethod/property where possible

and refactor lazy extractors accordingly.

This reduces the need to create extractor instances

devscripts/lazy_load_template.py

@@ -1,30 +1,28 @@
+import importlib
+import random
 import re
 
-from ..utils import bug_reports_message, write_string
+from ..utils import bug_reports_message, classproperty, write_string
 
 
 class LazyLoadMetaClass(type):
     def __getattr__(cls, name):
-        if '_real_class' not in cls.__dict__:
+        # "is_suitable" requires "_TESTS". However, they bloat the lazy_extractors
+        if '_real_class' not in cls.__dict__ and name not in ('is_suitable', 'get_testcases'):
             write_string(
                 'WARNING: Falling back to normal extractor since lazy extractor '
-                f'{cls.__name__} does not have attribute {name}{bug_reports_message()}')
-        return getattr(cls._get_real_class(), name)
+                f'{cls.__name__} does not have attribute {name}{bug_reports_message()}\n')
+        return getattr(cls.real_class, name)
 
 
 class LazyLoadExtractor(metaclass=LazyLoadMetaClass):
-    _module = None
-    _WORKING = True
-
-    @classmethod
-    def _get_real_class(cls):
+    @classproperty
+    def real_class(cls):
         if '_real_class' not in cls.__dict__:
-            mod = __import__(cls._module, fromlist=(cls.__name__,))
-            cls._real_class = getattr(mod, cls.__name__)
+            cls._real_class = getattr(importlib.import_module(cls._module), cls.__name__)
         return cls._real_class
 
     def __new__(cls, *args, **kwargs):
-        real_cls = cls._get_real_class()
-        instance = real_cls.__new__(real_cls)
+        instance = cls.real_class.__new__(cls.real_class)
         instance.__init__(*args, **kwargs)
         return instance