Usage
circle_grob(
r = unit(5, "mm"),
fill = "black",
col = "black",
lty = "solid",
lwd = 1,
cex = 1,
alpha = 1,
lineend = "round",
linejoin = "round",
linemitre = 10,
lex = 1,
name = NULL,
vp = NULL,
x = unit(0.5, "npc"),
y = unit(0.5, "npc"),
default.units = "mm"
)