$success
[1] 0

$message
$message$message
[1] "inherit"          "from class \"d\"" ""                 ""                

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

$message$wrap[[2]]
NULL



$df
[1] 0

$lvl
[1] 0

$success
[1] 0

$message
$message$message
[1] "be"    "\"d\"" "is"    "\"c\""

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

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




$df
[1] 0

$lvl
[1] 0

$success
[1] 0

$message
$message$message
[1] "be"    "\"d\"" "is"    "\"c\""

$message$wrap
$message$wrap[[1]]
class(NULL)[3]

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




$df
[1] 0

$lvl
[1] 0

# this should never happen in reality, but use alike check since not char char comparison

be
`alike` the corresponding element in target

$success
[1] 0

$message
$message$message
[1] "be"                                         
[2] "`alike` the corresponding element in target"
[3] ""                                           
[4] ""                                           

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

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




$df
[1] 0

$lvl
[1] 0

be
`alike` the corresponding element in target

be
`alike` the corresponding element in target

be
`alike` the corresponding element in target

$success
[1] 0

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

$message$wrap
$message$wrap[[1]]
class(NULL)[4]

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




$df
[1] 1

$lvl
[1] 0

$success
[1] 0

$message
$message$message
[1] "be"             "\"b\""          "is"             "\"data.frame\""

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

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




$df
[1] 0

$lvl
[1] 0

dimn2 <- list(a = letters[1:3], b = letters[4:6], c = letters[7:9])

dimn3 <- list(letters[1:3], b = letters[4:6], c = letters[7:9])

dimn4 <- list(letters[1:3], B = letters[4:6], C = letters[7:9])

dimn5 <- list(a = LETTERS[1:3], b = letters[4:6], c = letters[7:9])

dimn6 <- list(a = "", b = letters[4:6], c = letters[7:9])

dimn8 <- list(a = LETTERS[1:3], b = letters[4:6], c = letters[7:9], 
    d = letters[24:26])