Roxygen2 lets functions inherit parameter documentation across functions

[antongrau]

"You can inherit parameter descriptions from other functions using @inheritParams source_function. This tag will bring in all documentation for parameters that are undocumented in the current function, but documented in the source function. The source can be a function in the current package, via @inheritParams function, or another package, via @inheritParams package::function"

See: http://r-pkgs.had.co.nz/man.html

This should be applied to all map.functions