Unchecked return value

If the function returns an error value, the error value may be mistaken for a normal value. Value returned from a function is not checked for errors before being used.
/data/bazel_cache/1de52aaeb35278243ca29a4785ce7969/execroot/_main_/src/mongo/bson/json.cpp:791: CHECKED_RETURN 172207 Calling "readToken" without checking return value (as is done elsewhere 94 out of 99 times).