class Roda::RodaPlugins::Flash::FlashHash

used in the following request.
Simple flash hash, where assiging to the hash updates the flash

def []=(k, v)

Update the next hash with the given key and value. 
def []=(k, v)
  @next[k] = v
end

def discard(key=(no_arg=true))

no argument is given.
Remove given key from the next hash, or clear the next hash if 
def discard(key=(no_arg=true))
  if no_arg
    @next.clear
  else
    @next.delete(key)
  end
end

def initialize(hash={})

as a new empty hash.
Setup the next hash when initializing, and handle treat nil 
def initialize(hash={})
  super(hash||{})
  @next = {}
end

def keep(key=(no_arg=true))

next hash if no argument is given.
next hash, or copy all entries from the current hash to the
Copy the entry with the given key from the current hash to the 
def keep(key=(no_arg=true))
  if no_arg
    @next.merge!(self)
  else
    self[key] = self[key]
  end
end

def sweep

Replace the current hash with the next hash and clear the next hash. 
def sweep
  replace(@next)
  @next.clear
  self
end