10 files declare their use of ParserResult in Feeds 8.3

AfterParseBaseTest.php in tests/src/Unit/EventSubscriber/AfterParseBaseTest.php

CsvParser.php in src/Feeds/Parser/CsvParser.php

FeedRefreshTest.php in tests/src/Unit/Plugin/QueueWorker/FeedRefreshTest.php

FeedsExecutableTest.php in tests/src/Unit/FeedsExecutableTest.php

LazySubscriberTest.php in tests/src/Unit/EventSubscriber/LazySubscriberTest.php

OpmlParser.php in src/Feeds/Parser/OpmlParser.php

ParserResultTest.php in tests/src/Unit/Result/ParserResultTest.php

ParserWithMappingForm.php in tests/modules/feeds_test_plugin/src/Feeds/Parser/ParserWithMappingForm.php

SitemapParser.php in src/Feeds/Parser/SitemapParser.php

SyndicationParser.php in src/Feeds/Parser/SyndicationParser.php