* Add Operation Servers to {operation}Call method
* add getter/setter methods
Add methods for hostIndex and customBaseUrl
* Fix return types for getters
* Add custom baseUrl logic
if you dont specifically declare a custom base url using the set method then it uses the 1st server in the operation host index array
if no custom url is set and the operation base path array is empty however, the call throws an exception
* Update server selection logic
First checks to see if a custom url is provided
If not, checks to see if operation level server is defined and uses the supplied host index (default 0)
If neither is supplied, uses the ApiClient default base path
* Update samples and docs
