vetr:::attr_compare(matrix(integer(), 3, 3, dimnames = list(A = LETTERS[1:3], 
    letters[1:3])), matrix(integer(), 3, 3, dimnames = list(a = LETTERS[1:3], 
    b = letters[1:3])))

$success
[1] 0

$message
$message$message
[1] "be"    "\"A\"" "is"    "\"a\""

$message$wrap
$message$wrap[[1]]
names(dimnames(NULL))[1]

$message$wrap[[2]]
$message$wrap[[2]][[1]]
NULL




$df
[1] 0

$lvl
[1] 5

vetr:::attr_compare(structure(list(integer(), character())), 
    data.frame(a = 1:10, b = letters[1:10]))

vetr:::attr_compare(structure(list(integer(), character()), class = "data.frame"), 
    data.frame(a = 1:10, b = letters[1:10]))

$success
[1] 1

$message
NULL

$df
[1] 1

$lvl
[1] 0

vetr:::attr_compare(structure(unname(data.frame(integer(), character())), 
    class = "data.frame"), data.frame(a = 1:10, b = letters[1:10]))

vetr:::attr_compare(structure(list(), welp = list()), structure(list("hello"), 
    welp = list(NULL, 1:3), belp = 1:3))

vetr:::attr_compare(structure(list(), welp = list(NULL)), structure(list("hello"), 
    welp = list(NULL, 1:3), belp = 1:3))

$success
[1] 0

$message
$message$message
[1] "be" "1"  "is" "2" 

$message$wrap
$message$wrap[[1]]
length(attr(NULL, "welp"))

$message$wrap[[2]]
$message$wrap[[2]][[1]]
NULL

$message$wrap[[2]][[2]]
[1] "welp"




$df
[1] 0

$lvl
[1] 6

vetr:::attr_compare(structure(list(), welp = list(), belp = 1:3), 
    structure(list("hello"), welp = list(NULL, 1:3)))

$success
[1] 0

$message
$message$message
[1] "have"               "attribute \"belp\"" ""                  
[4] ""                  

$message$wrap
$message$wrap[[1]]
NULL

$message$wrap[[2]]
NULL



$df
[1] 0

$lvl
[1] 7

vetr:::attr_compare(structure(list(), class = letters[1:3]), 
    structure(list("hello"), class = letters[1:3]))

vetr:::attr_compare(structure(list(), class = letters[1:3]), 
    structure(list("hello"), class = letters[1:4]))

$success
[1] 0

$message
$message$message
[1] "be"    "\"a\"" "is"    "\"b\""

$message$wrap
$message$wrap[[1]]
class(NULL)[2]

$message$wrap[[2]]
$message$wrap[[2]][[1]]
NULL




$df
[1] 0

$lvl
[1] 0