code: function flattenChildren(children) {
    if (children == null) {
      return children;
    }
    var result = {};
    traverseAllChildren(children, flattenSingleChildIntoContext, result);
    return result;
  }
docs: Flattens children that are typically specified as `props.children`. Any null
  children will not be included in the resulting object.
  @return {!object} flattened children keyed by name.