如何在r中有多个组的情况下绘制跨时间图？

install.packages("ggplot2")
install.packages("reshape2")

library(ggplot2)
library(reshape2)

group time value
A     1    10
A     2    15
B     1    8
B     2    12

melted_data <- melt(data, id.vars = c("group", "time"), measure.vars = "value")

ggplot(melted_data, aes(x = time, y = value, color = group)) +
  geom_line()

ggplot(melted_data, aes(x = time, y = value, color = group)) +
  geom_line() +
  labs(title = "跨时间图",
       x = "时间",
       y = "数值",
       color = "组") +
  theme(legend.position = "top")