from json_transformer import JSONTransformer
import json

mappings = {"firstName": "first_name", "lastName": "last_name"}
transformers = {
    'age': lambda x: x + 1,
    'name': str.upper
}

transformer = JSONTransformer(mappings=mappings, transformers=transformers)

data = {"age": 30, "lastName": "Doe", "firstName": "John"}
transformed = transformer.transform(data)
print(json.dumps(transformed, indent=2))