def METHOD_NAME(cls, field, model):
    try:
        # If model is not present in dict, init its schema and its field subschemas
        if model not in cls.models_to_schema_and_fields_dict:
            schema = cls.init_model_schemas(model)
            if not schema:
                error_msg = f"ModelValidation failed. Are you sure the schema for {model} is present and proper?"
                raise RuntimeError(error_msg)
        if field == None:
            return cls.models_to_schema_and_fields_dict[model]["model_schema"]
        # Else, return the specified field schema
        return cls.models_to_schema_and_fields_dict[model]["field_schema"][field]
    except BaseException as e:
        raise e