如何停止tidyr展开按字母顺序对列进行排序

library(tidyr)

# 创建一个示例数据框
df <- data.frame(
  id = c(1, 2, 3),
  name = c("John", "Alice", "Bob"),
  subjects = c("Math, Science", "English, History", "Physics, Chemistry")
)

# 使用tidyr展开列，并禁用排序
df_unnest <- tidyr::separate_rows(df, subjects, sep = ",", convert = TRUE, sort = FALSE)

# 输出展开后的数据框
print(df_unnest)