robustify for Java 6 #834
robustify for Java 6 #834

tgvaughan/beast2,Anaphory/beast2,Anaphory/beast2,tgvaughan/beast2,tgvaughan/beast2,CompEvol/beast2,CompEvol/beast2,tgvaughan/beast2,CompEvol/beast2,Anaphory/beast2,CompEvol/beast2,Anaphory/beast2