ark tweet tagger fails with a conll input file with just one column

[negrinho]

./ark-tweet-nlp-0.3.2/runTagger.sh --input-format conll data/test.txt
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1
at cmu.arktweetnlp.io.CoNLLReader.sentenceFromLines(CoNLLReader.java:55)
at cmu.arktweetnlp.io.CoNLLReader.readFile(CoNLLReader.java:32)
at cmu.arktweetnlp.RunTagger.runTaggerInEvalMode(RunTagger.java:161)
at cmu.arktweetnlp.RunTagger.runTagger(RunTagger.java:87)
at cmu.arktweetnlp.RunTagger.main(RunTagger.java:364)

The file test.txt was:

This
is
a
test
!

Adding a (tab separated) dummy column solves the problem (but still, it ought work with files with just one column):
This 1
is 2
a 3
test 4
! 5