only allow single expression after 'in'; tweak error recovery when waiting for colon (PY-9561)
report missing identifier after 'as' (PY-9853)
rename some methods and cleanup code to make logic clearer
failing test for PY-10319
Cleanup (formatting)
Todo
EA-51650 - assert: JavaDocInfoGenerator.getDocComment
EA-51491 - assert: DocumentImpl.createRangeMarker