Replace public fields with properties

[ob-stripe]

r? @remi-stripe
cc @stripe/api-libraries

Replace public fields by private fields encapsulated by public properties.

Public fields in public classes do not respect the encapsulation principle and has three main disadvantages:

Additional behavior such as validation cannot be added.
The internal representation is exposed, and cannot be changed afterwards.
Member values are subject to change from anywhere in the code and may not meet the programmer's assumptions.
By using private fields and public properties (set and get), unauthorized modifications are prevented. Properties also benefit from additional protection (security) features such as Link Demands.

Note that due to optimizations on simple properties, public fields provide only very little performance gain.

[remi-stripe]

Does that mean anyone can set this?

[ob-stripe]

Yep. I also have doubts whether this should be allowed, but wanted to maintain the current behavior.