new_contents: # Copyright 2022 DeepMind Technologies Limited.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     https://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  """Tools to help with parsing and procedurally generating ascii maps."""
  
  from collections.abc import Mapping, Sequence
  from typing import Any, Union
  
  
  def a_or_b_with_odds(a_descriptor: Union[str, Mapping[str, Any]],
                       b_descriptor: Union[str, Mapping[str, Any]],
                       odds: Sequence[int]) -> Mapping[str, Any]:
    """Return a versus b with specified odds.
  
    Args:
        a_descriptor: One possibility. May be either a string or a dict that can
            be read by the map parser.
        b_descriptor: The other possibility. May be either a string or a dict that
            can be read by the map parser.
        odds: odds[0] is the number of outcomes where a is returned. odds[1] is
            the number of outcomes where b is returned. Thus the probability of
            returning a is odds[0] / sum(odds) and the probability of returning
            b is odds[1] / sum(odds).
  
    Returns:
        The dict descriptor that can be used with the map parser to sample either
        a or b at the specified odds.
    """
    a_odds, b_odds = odds
    choices = [a_descriptor] * a_odds + [b_descriptor] * b_odds
    return {"type": "choice", "list": choices}
  
subject: Add map helpers for use in future melting pot version.