Changes to Get Multivariate Event Collection

added the required property multivariate_contract/price_level_structure to the response with the 200 status

added the required property multivariate_contract/price_ranges to the response with the 200 status

added the optional property multivariate_contract/exchange_index to the response with the 200 status

removed the optional property service from the response with the 400 status

removed the optional property service from the response with the 404 status

removed the optional property service from the response with the 500 status

api tag multivariate added

api tag collection removed

the response property multivariate_contract/associated_events/items/size_max became nullable for the status 200

the response property multivariate_contract/associated_events/items/size_min became nullable for the status 200

added the non-success response with the status 400

added the non-success response with the status 404

added the non-success response with the status 500

the response property multivariate_contract became required for the status 200

the response property multivariate_contract/associated_event_tickers became required for the status 200

the response property multivariate_contract/associated_events became required for the status 200

the response property multivariate_contract/associated_events/items/active_quoters became required for the status 200

the response property multivariate_contract/associated_events/items/is_yes_only became required for the status 200

the response property multivariate_contract/associated_events/items/ticker became required for the status 200

the response property multivariate_contract/close_date became required for the status 200

the response property multivariate_contract/collection_ticker became required for the status 200

the response property multivariate_contract/description became required for the status 200

the response property multivariate_contract/functional_description became required for the status 200

the response property multivariate_contract/is_all_yes became required for the status 200

the response property multivariate_contract/is_ordered became required for the status 200

the response property multivariate_contract/is_single_market_per_event became required for the status 200

the response property multivariate_contract/open_date became required for the status 200

the response property multivariate_contract/series_ticker became required for the status 200

the response property multivariate_contract/size_max became required for the status 200

the response property multivariate_contract/size_min became required for the status 200

the response property multivariate_contract/title became required for the status 200

added the optional property multivariate_contract/associated_events to the response with the 200 status