static inheritChild(context, callback, child) {
    const MpdUtils = shaka.dash.MpdUtils;
    const nodes = MpdUtils.getNodes(context, callback);

    const TXml = shaka.util.TXml;
    let result = null;
    for (const node of nodes) {
      result = TXml.findChild(node, child);
      if (result) {
        break;
      }
    }
    return result;
  }
Searches the inheritance for a Segment* with the given child.

@param {shaka.dash.DashParser.Context} context
@param {function(?shaka.dash.DashParser.InheritanceFrame):
  ?shaka.extern.xml.Node} callback
  Gets the Element that contains the child to inherit.
@param {string} child
@return {?shaka.extern.xml.Node}