Pydantic class inheritance

Question

I am doing some inheritance in Pydantic.

Here is my code:

from typing import Dict, Any, List, Optional, Mapping
from pydantic import BaseModel, Field, ValidationError, validator
from enum import Enum



class PartitionCountType(int, Enum):
    one = 1
    two = 2
    three = 3
    four = 4
    five = 5
    six = 6

class TopicConfigType(BaseModel):
    env: Optional[str] = Field(None, description="The environment that the topic is in.")
    cleanup_policy: Optional[str] = Field(None, description="The cleanup policy of the topic.") 
    delete_retention_ms: Optional[str] = Field(None, description="The delete retention in milliseconds of the topic.") 
    max_compaction_lag_ms: Optional[str] = Field(None, description="The maximum compaction lag in milliseconds of the topic.") 
    max_message_bytes: Optional[str] = Field(None, description="The maximum message bytes of the topic.") 
    message_timestamp_difference_max_ms: Optional[str] = Field(None, description="The maximum message timestamp difference in milliseconds of the topic.") 
    message_timestamp_type: Optional[str] = Field(None, description="The message timestamp type of the topic.")
    min_compaction_lag_ms: Optional[str] = Field(None, description="The minimum compaction lag in milliseconds of the topic.")
    retention_bytes: Optional[str] = Field(None, description="The retention bytes of the topic.") 
    retention_ms: Optional[str] = Field(None, description="The retention in milliseconds of the topic.") 
    segment_bytes: Optional[str] = Field(None, description="The segment bytes of the topic.") 
    segment_ms: Optional[str] = Field(None, description="The segment in milliseconds of the topic.")  



class Topic(BaseModel):
    """
    Topic variables that are used throughout the program.
    """
    env: Optional[str] = Field(None, description="The environment that the topic is in.")
    topic_name: str = Field(..., description="The name of the topic.")
    partitions_count: PartitionCountType = Field(None, description="The number of partitions that the topic will have.")
    config: TopicConfigType = Field (description="The configuration of the topic.")

I am looking to do validation on the config mapping with the validator function in Pydantic. When I run this code cdktf synth im getting the following error

 TypeError: type of argument config must be one of (Mapping[str, str], NoneType); got custom_types.confluent.topic.TopicConfigType instead

Not sure why. The accepted type for config is Mapping[str,str] but I am passing that with value TopicConfigType. Seems off. Any insight would be helpful

Above is what Ive tried

Here is my construct for KafkaTopic

from imports.confluent.kafka_topic import KafkaTopic
from custom_types.confluent.topic import PartitionCountType
from custom_types.confluent.topic import TopicConfigType


class DTTopic(Construct):

    topic_name = KafkaTopic

    def __init__(self, scope: Construct, id:str, topic_name: str, partitions_count: PartitionCountType, topic_config: TopicConfigType, ):
        super().__init__(scope, id)
        
        self.topic_name = KafkaTopic(
            self, "topic_name", topic_name=topic_name, partitions_count=partitions_count, topic_config=topic_config
        )```


Here is me passing the data to the Confluent Provider
```        # Load the Confluent topics
        topics = {}

        if type(confluent_generated_config_env.providers.confluent) != type(None):

            for (k,v) in confluent_generated_config_env.providers.confluent.topics.items():
                topic_id = f"topic_{k}"  # Use a unique identifier for each topic

                topics[k] = DTTopic(
                    self,
                    topic_id,
                    topic_name=v.topic_name, 
                    partitions_count=v.partitions_count, 
                    config=v.topic_config
                )```