code: def to_json(self, default_mapping=None):
          
          return json.dumps(self.to_dict(), default=json_convertor_default(default_mapping=default_mapping))
docs: Dump json of the text view.
          **Parameters**
  
          default_mapping : default_mapping, dictionary(optional), a dictionary of mapping of different types to json types.
  
          by default DeepDiff converts certain data types. For example Decimals into floats so they can be exported into json.
          If you have a certain object type that the json serializer can not serialize it, please pass the appropriate type
          conversion through this dictionary.
  
          **Example**
  
          Serialize custom objects
              >>> class A:
              ...     pass
              ...
              >>> class B:
              ...     pass
              ...
              >>> t1 = A()
              >>> t2 = B()
              >>> ddiff = DeepDiff(t1, t2)
              >>> ddiff.to_json()
              TypeError: We do not know how to convert <__main__.A object at 0x10648> of type <class '__main__.A'> for json serialization. Please pass the default_mapping parameter with proper mapping of the object to a basic python type.
  
              >>> default_mapping = {A: lambda x: 'obj A', B: lambda x: 'obj B'}
              >>> ddiff.to_json(default_mapping=default_mapping)
              '{"type_changes": {"root": {"old_type": "A", "new_type": "B", "old_value": "obj A", "new_value": "obj B"}}}'