def delete(tokens)
      unless tokens.instance_of? Array
        tokens = [ tokens ]
      end
      removed = tokens.map do |token|
        validate_token!(token)
        delete_token(token)
      end
      if removed.size == 1
        removed.first
      else
        removed
      end
    end
def delete(tokens)
      unless tokens.instance_of? Array
        tokens = [ tokens ]
      end
      removed = tokens.map do |token|
        validate_token!(token)
        delete_token(token)
      end
      if removed.size == 1
        removed.first
      else
        removed
      end
    end
Deletes the +token+ from the marking.
 To do it you must first find the token in
 the marking.