Fixed Issue #83

[thynash]

what this pr does is as follows -

1. Ensured that all fields using field(default_factory=...) are now correctly formatted.

2)Ensured _index is properly initialized with init=False

fixes : #83

[salesforce-cla]

Thanks for the contribution! Before we can merge this, we need @thynash to sign the Salesforce Inc. Contributor License Agreement.