When an object is about to be removed from R it is first deprecated and
should include a call to .Deprecated.
.Deprecated(new, package=NULL, msg,
old = as.character(sys.call(sys.parent()))[1L])character string: A suggestion for a replacement function.
character string: The package to be used when suggesting where the deprecated function might be listed.
character string: A message to be printed, if missing a default message is used.
character string specifying the function (default) or usage which is being deprecated.
.Deprecated("<new name>") is called from deprecated
functions. The original help page for these functions is often
available at help("oldName-deprecated") (note the quotes).
Functions should be listed in help("pkg-deprecated") for an
appropriate pkg, including base.
.Deprecated signals a warning of class deprecatedWarning
with fields old, new, and package.
base-deprecated and so on which list the deprecated functions
in the packages.