The question itself is clear:
If you paste a character(0) with some string, it will automatic disappear,the code and the result is below:
paste(paste(NULL,character(0),sep = "\n"),character(0),sep = "\n")
character(0)
However,if you wrap the character(0) with list, then then code and result is:
paste(paste(NULL,list(character(0)),sep = "\n"),list(character(0)),sep = "\n")
[1] "\ncharacter(0)\ncharacter(0)"
