code: function incrementVersion(metadata, version) {
    const new_metadata = Object.assign({}, metadata);
    new_metadata[version] = getVersion(metadata, version) + 1;
    return {
      metadata: new_metadata,
    };
  }
docs: Increments metadata object version numbers.
  
  @param {Object} metadata The state.map.metadata.
  @param {string} version The metadata object to be incremented.
  
  @returns {Object} The new state.map.metadata object with the incremented version.