opennlp.tools.parser.Parse.remove() throws IndexOutOfBoundsException

Parse.remove() throws IndexOutOfBoundsException if you attempt to remove the last child node of the current node (i.e. if you call remove(0) and this node has only one sub-node).
Some background info: I was trying to remove the TK nodes from a parse.

I attached the diff file for the change fixing the bug.
The change is simple: a supplementary check:

if(! parts.isEmpty())

before rebuilding the span.

Thank you
Ioan

P.S. this is my first reported bug, so please be gentle Please tell me if something is wrong with this issue, so that I fix it.