defineDeprecationWarning = function(methodName, info) {
    try {
      Object.defineProperty(ReactComponent.prototype, methodName, {
        get: function() {
          ("production" !== process.env.NODE_ENV ? warning(
            false,
            '%s(...) is deprecated in plain JavaScript React classes. %s',
            info[0],
            info[1]
          ) : null);
          return undefined;
        }
      });
    } catch (x) {
      // IE will fail on defineProperty (es5-shim/sham too)
    }
  }
If a particular environment requires that some resources be cleaned up,
specify this in the injected Mixin. In the DOM, we would likely want to
purge any cached node ID lookups.

@private