I have a dataframe:

```
inde.vars <- structure(list(Group = c("CUR", "CUR", "CUR", "CUR", "CUR", "CUR", 
"CUR", "CUR", "CUR", "CUR"), Subject = c("0", "0", "0", "0", 
"0", "0", "0", "0", "0", "0"), Condition = c("L1", "L1", "L1", 
"L2", "L2", "L2", "L3", "L3", "L3", "L4"), Trial = c(1L, 2L, 
3L, 1L, 2L, 3L, 1L, 2L, 3L, 1L)), row.names = c(1L, 68L, 76L, 
151L, 226L, 301L, 376L, 451L, 464L, 539L), class = "data.frame")

classes.group <- inde.vars[,1]

```

What do I need to do to assign object name or some identifier, for example, "Group" for character object `classes.group` so I get someting like:

```
names(classes.group)
"Group"

```