OWDistanceMap: Don't report plot if no data
OWDistanceMap: Don't report plot if no data

marinkaz/orange3,cheral/orange3,qPCR4vir/orange3,marinkaz/orange3,qPCR4vir/orange3,marinkaz/orange3,cheral/orange3,kwikadi/orange3,qPCR4vir/orange3,kwikadi/orange3,marinkaz/orange3,marinkaz/orange3,marinkaz/orange3,qPCR4vir/orange3,kwikadi/orange3,qPCR4vir/orange3,qPCR4vir/orange3,cheral/orange3,kwikadi/orange3,kwikadi/orange3,kwikadi/orange3,cheral/orange3,cheral/orange3,cheral/orange3