Returns a ApiFuture that will be completed when there are messages available.
Unfinished existing ApiFuture returned by onData() will be abandoned and superseded by
new onData() call.
CheckedApiException will be set to the Future if there is underlying permanent
error.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-22 UTC."],[],[]]