[notes] This is a regression test for antlr/antlr4#1545, case 2. [type] Parser [grammar] grammar OpenDeviceStatement; program : statement+ '.' ; statement : 'OPEN' ( 'DEVICE' ( (OPT1) | OPT2 | OPT3 )? )+ {} ; OPT1 : 'OPT-1'; OPT2 : 'OPT-2'; OPT3 : 'OPT-3'; WS : (' '|'\n')+ -> channel(HIDDEN); [start] statement [input] OPEN DEVICE DEVICE [output] """OPEN DEVICE DEVICE """