I assume that if I have 2 identical data.frames, the R digest function should return the same result. Consider these two data frames. 

```
library(digest)
library(dplyr)
df1 <- tibble(a =1:5, b=11:15)
df2 <-  df1 %>% 
        mutate(c=b-1) %>% 
        select(-c)

```

Both data.frames are identical when printed,

```
> df1
# A tibble: 5 × 2
  a     b
  <int> <int>
1     1    11
2     2    12
3     3    13
4     4    14
5     5    15

```

or compared: 

```
> df1 ==df2
        a    b
[1,] TRUE TRUE
[2,] TRUE TRUE
[3,] TRUE TRUE
[4,] TRUE TRUE
[5,] TRUE TRUE

```

However, the digest function returns different results:

```
> digest(df1)
[1] "4f82aa1035792a0acf304242ce6ad3ec"
> digest(df2)
[1] "3b7e697af67e8e36ba9b59aef69db304"

```

I would expect the digest function to result in the same result!!
Is there a better way to compare identical data.frames?