CRAN performing additional S3 generics checks in rdevel

[LHMarshall]

See the following link for where other people have fixed this: https://github.com/joshuaulrich/quantmod/commit/0c85510b9f7dc7334feffaaf7978bef04fc60b9c

* checking S3 generic/method consistency ... NOTE
Mismatches for apparent methods not registered:
plot:
  function(x, ...)
plot.layout:
  function(which, pages)

Mismatches for methods registered for non-generic:
ddf:
  function(dsmodel, mrmodel, data, method, meta.data, control)
ddf.ds:
  function(model, data, meta.data, control, call, method)

ddf:
  function(dsmodel, mrmodel, data, method, meta.data, control)
ddf.io:
  function(dsmodel, mrmodel, data, meta.data, control, call)

ddf:
  function(dsmodel, mrmodel, data, method, meta.data, control)
ddf.io.fi:
  function(model, data, meta.data, control, call, method)

ddf:
  function(dsmodel, mrmodel, data, method, meta.data, control)
ddf.rem:
  function(dsmodel, mrmodel, data, meta.data, control, call)

ddf:
  function(dsmodel, mrmodel, data, method, meta.data, control)
ddf.rem.fi:
  function(model, data, meta.data, control, call, method)

ddf:
  function(dsmodel, mrmodel, data, method, meta.data, control)
ddf.trial:
  function(dsmodel, mrmodel, data, meta.data, control, call)

ddf:
  function(dsmodel, mrmodel, data, method, meta.data, control)
ddf.trial.fi:
  function(model, data, meta.data, control, call, method)
See section 'Registering S3 methods' in the 'Writing R Extensions'
manual.