class DEBUGGER__::AbbrevCommand

def search str, if_none = nil
  trie = @trie
  str.each_char do |c|
    if trie = trie[c]
      return trie.type if trie.type
    else
      return if_none
    end
  end
  yield trie.candidates.map{|s| str + s} if block_given?
  if_none
end