AST distinction between parameter-less and empty-parameter-list methods

hi,

how can i distinguish def x from def x() in an AST construction?

this:

DefDef(
NoMods withPosition (Flags.METHOD, NoPosition),
"x"
Nil, // tparams
Nil, // vparams
TypeTree( NoType ),
EmptyTree // rhs
)

produces def x ... but how do i get the def x()? i tried to use List( Nil ) in place of vparams, but that doesn't change anything it seems.

thanks, -sciss-