docs: def get_class_field(cls, field_name):
          """
          Add management of dynamic fields: if a normal field cannot be retrieved,
          check if it can be a dynamic field and in this case, create a copy with
          the given name and associate it to the model.
          """
          try:
              field = super(ModelWithDynamicFieldMixin, cls).get_class_field(field_name)
          except AttributeError:
              # the "has_field" returned True but getattr raised... we have a DynamicField
              dynamic_field = cls._get_dynamic_field_for(field_name)
              field = cls._add_dynamic_field_to_model(dynamic_field, field_name)
  
          return field