readGmane(...)function with the signature elem, load,
id:
list with the two named elements
content and uri. The first element must hold the
document corpus to be read in, the second element must hold a
call to the document corpus. The call is evaluated upon
a request for load on demand.}logical value indicating whether the
document corpus should be immediately loaded into memory.character representing a unique
identification string for the returned text document.content