library (group) names can't be numerical

[Phlya]

Raises an error on lines

distiller-nf/distiller.nf

Line 659 in 689df3e

.filter{ it[1].contains(it[2]) }

and

distiller-nf/distiller.nf

Line 717 in 689df3e

.filter{ it[1].contains(it[2]) }

“Cannot invoke method contains() on null object”

Not sure about library names, only tried group names.