def method_missing(attr_name)
      member_sym = attr_name.id2name.to_sym
      self[member_sym]
    rescue ArgumentError # `member_sym` field doesn't exist.
      raise(NoMethodError.new("undefined method '#{attr_name}' for #{self}"))
    end
def method_missing(attr_name)
      member_sym = attr_name.id2name.to_sym
      self[member_sym]
    rescue ArgumentError # `member_sym` field doesn't exist.
      raise(NoMethodError.new("undefined method '#{attr_name}' for #{self}"))
    end
Provides accessor methods for the members of the MeCab struct.
 @param attr_name [String] attribute name
 @return member values for the MeCab struct
 @raise [NoMethodError] if `attr_name` is not a member of this MeCab struct