TODO...
Usage:
xan cluster <column> [options] [<input>]
xan cluster --help
cluster options:
-k, --key <expr> An expression to evaluate to generate a key
for each row by transforming the selected cell.
Common options:
-h, --help Display this message
-o, --output <file> Write output to <file> instead of stdout.
-n, --no-headers When set, the first row will not be evaled
as headers.
-d, --delimiter <arg> The field delimiter for reading CSV data.
Must be a single character.