module Rake::TaskManager

def in_namespace(name)

an anonymous namespace if +name+ is nil.
Evaluate the block in a nested namespace named +name+. Create

def in_namespace(name)
  name ||= generate_name
  @scope = Scope.new(name, @scope)
  ns = NameSpace.new(self, @scope)
  yield(ns)
  ns
ensure
  @scope = @scope.tail
end