function createElement(type, config, children) {
    var propName; // Reserved names are extracted

    var props = {};
    var key = null;
    var ref = null;
    var self = null;
    var source = null;

    if (config != null) {
      if (hasValidRef(config)) {
        ref = config.ref;

        {
          warnIfStringRefCannotBeAutoConverted(config);
        }
      }

      if (hasValidKey(config)) {
        {
          checkKeyStringCoercion(config.key);
        }

        key = '' + config.key;
      }

      self = config.__self === undefined ? null : config.__self;
      source = config.__source === undefined ? null : config.__source; // Remaining properties are added to a new props object

      for (propName in config) {
        if (hasOwnProperty.call(config, propName) && !RESERVED_PROPS.hasOwnProperty(propName)) {
          props[propName] = config[propName];
        }
      }
    } // Children can be more than one argument, and those are transferred onto
    // the newly allocated props object.


    var childrenLength = arguments.length - 2;

    if (childrenLength === 1) {
      props.children = children;
    } else if (childrenLength > 1) {
      var childArray = Array(childrenLength);

      for (var i = 0; i < childrenLength; i++) {
        childArray[i] = arguments[i + 2];
      }

      {
        if (Object.freeze) {
          Object.freeze(childArray);
        }
      }

      props.children = childArray;
    } // Resolve default props


    if (type && type.defaultProps) {
      var defaultProps = type.defaultProps;

      for (propName in defaultProps) {
        if (props[propName] === undefined) {
          props[propName] = defaultProps[propName];
        }
      }
    }

    {
      if (key || ref) {
        var displayName = typeof type === 'function' ? type.displayName || type.name || 'Unknown' : type;

        if (key) {
          defineKeyPropWarningGetter(props, displayName);
        }

        if (ref) {
          defineRefPropWarningGetter(props, displayName);
        }
      }
    }

    return ReactElement(type, key, ref, self, source, ReactCurrentOwner.current, props);
  }
Create and return a new ReactElement of the given type.
See https://reactjs.org/docs/react-api.html#createelement