googleVis display - pop up window customization

Question

I coded a sankey diagram in googleVis r pacakge:

All<- data.frame(From=c('Uvoz okroglega lesa', 'Proizvodnja okroglega lesa', 'Poraba okroglega lesa', 'Poraba okroglega lesa',
                                 'Zage','Zage','Zage', 'Zagan les','Uvoz zaganega lesa','Zagan les','Ostalo zagan les','Ostalo zagan les', 'Zage'),
                          To=c('Poraba okroglega lesa','Poraba okroglega lesa', 'Izvoz okroglega lesa', 'Zage', 'Celuloza in plosce',
                               'Energetska raba','Zagan les', 'Lesni ostanki','Ostalo zagan les','Ostalo zagan les',
                               'Poraba zaganega lesa v Sloveniji', 'Izvoz zaganega lesa','Furnir'),
                          Quantity=c(0.460, 5.100, 2.393, 3.167, 0.560, 1.377, 1.200, 0.430, 0.902, 0.770, 0.647, 1.025, 0.030),
                          Year=2013)

Sankey = gvisSankey(All,from="From", to="To", weight="Quantity",
                    options=list(width = "1200",
                                 height = "600",
                                 sankey="{
                                 link: {colorMode: 'gradient', color: { fill: '#green' } },
                                 node: {nodePadding: 80, width:50, color: { fill: '#a61d4c'} },
                                 label: { color: '#871b47',fontSize: 50 } }"))

plot(Sankey) 

I would like to customize a pop-up window of categories, e.g. adding a units.

PrtScr of what I mean is provided bellow: