class SyntaxTree::Parser

def on_mrhs_add_star(mrhs, value)

on_mrhs_add_star: (MRHS mrhs, untyped value) -> MRHS
:call-seq: 
def on_mrhs_add_star(mrhs, value)
  beginning = consume_operator(:*)
  ending = value || beginning
  arg_star =
    ArgStar.new(
      value: value,
      location: beginning.location.to(ending.location)
    )
  location =
    if mrhs.parts.empty?
      arg_star.location
    else
      mrhs.location.to(arg_star.location)
    end
  MRHS.new(parts: mrhs.parts << arg_star, location: location)
end