Adding Multiple Text Fonts to a Custom JSON Theme

This might be a silly question but i created a JSON theme (below) but i want to be able to bring in not just the Roboto Font but other fonts within the Roboto family such as Roboto Meduim, Roboto Light, Roboto Bold and ect. Doest anyone know how to modify what i have to make that happen?

{"name":"MyTheme","dataColors":["#ff4019","#f47c24","#4d9436","#325D84","#972e4c","#3DDC97","#0099c2","#ffd723"],"visualStyles":{"*":{"*":{"*":[{"fontSize":12,"fontFamily":"Roboto","color":{"solid":{}}}]}}}}

Thank you,