Fixed some misbehaviours regarding question() + added #import functionality when restoring

src/core/builtin_concepts.py

@@ -181,6 +181,7 @@ BuiltinErrors = [str(e) for e in {
     BuiltinConcepts.NOT_FOUND,
     BuiltinConcepts.INVALID_LESSER_OPERATION,
     BuiltinConcepts.INVALID_GREATEST_OPERATION,
+    # DO NOT PUT NOT_INITIALIZED. It's not an error
 }]
 
 """
@@ -534,3 +535,15 @@ class PythonSecurityError(Concept):
         self.set_value("column", column)  # column number
         self.set_value(ConceptParts.BODY, source_code)  # code being executed
         self.metadata.is_evaluated = True
+
+
+class NotFound(Concept):
+    def __init__(self, body=None):
+        super().__init__(BuiltinConcepts.NOT_FOUND,
+                         True,
+                         False,
+                         BuiltinConcepts.NOT_FOUND)
+        self.set_value(ConceptParts.BODY, body)
+
+    def __repr__(self):
+        return f"({self.metadata.id}){self.metadata.name}, body={self.get_value(ConceptParts.BODY)}"