class Gherkin::AstNode

def add(rule_type, obj)
  @_sub_items[rule_type].push(obj)
end

def get_items(rule_type)
  @_sub_items[rule_type]
end

def get_single(rule_type)
  @_sub_items[rule_type].first
end

def get_token(token_type)
  get_single(token_type)
end

def get_tokens(token_type)
  @_sub_items[token_type]
end

def initialize(rule_type)
  @rule_type = rule_type
  @_sub_items = Hash.new { |hash, key| hash[key] = [] } # returns [] for unknown key
end