Default dimnames() converts a zero-length character vector to NULL,
leading to the improper functioning of subsetting functions. These are safer
methods to set the dimnames of a dfm or fcm object.
Usage
set_dfm_dimnames(x) <- value
set_dfm_docnames(x) <- value
set_dfm_featnames(x) <- value
set_fcm_dimnames(x) <- value
set_fcm_featnames(x) <- value