allow input to be null, if null check is needed should be done higher
allow input to be null, if null check is needed should be done higher

fantasy86/jline2,scala/scala-jline,msaxena2/jline2,tkruse/jline2,scala/scala-jline,kaulkie/jline2,DALDEI/jline2,renew-tgi/jline2,ctubbsii/jline2