org-babel-expand-body:R has this arglist:
(body params &optional &graphics-file)
which seems to work OK.
But edebug does not like it. The error message is:
edebug-syntax-error: Invalid read syntax: "Failed matching"...
when I try to instrument the function.
Unless somebody can point me toward a rationale for the `&' prefixed to
`graphics-file', I will remove it.
Chuck
