How to use the element-ui/src/utils/merge function in element-ui

}

  if (typeof Promise !== 'undefined') {
    return new Promise((resolve, reject) => { // eslint-disable-line
      msgQueue.push({
        options: merge({}, defaults, MessageBox.defaults, options),
        callback: callback,
        resolve: resolve,
        reject: reject
      });

      showNextMsg();
    });
  } else {
    msgQueue.push({
      options: merge({}, defaults, MessageBox.defaults, options),
      callback: callback
    });

    showNextMsg();
  }
};

const getDefaultColumn = function (type, options) {
  const column = {};

  objectAssign(column, defaults[type || 'default']);

  for (let name in options) {
    if (options.hasOwnProperty(name)) {
      const value = options[name];
      if (typeof value !== 'undefined') {
        column[name] = value;
      }
    }
  }

  if (!column.minWidth) {
    column.minWidth = 80;
  }

  column.realWidth = column.width === undefined ? column.minWidth : column.width;

const getDefaultColumn = function(type, options) {
  const column = {};

  objectAssign(column, defaults[type || 'default']);

  for (let name in options) {
    if (options.hasOwnProperty(name)) {
      const value = options[name];
      if (typeof value !== 'undefined') {
        column[name] = value;
      }
    }
  }

  if (!column.minWidth) {
    column.minWidth = 80;
  }

  column.realWidth = column.width || column.minWidth;

field.validate('', (message, field) => {
            if (message) {
              valid = false;
            }
            invalidFields = objectAssign({}, invalidFields, field);
            if (typeof callback === 'function' && ++count === this.fields.length) {
              callback(valid, invalidFields);
            }
          });
        });

MessageBox.confirm = (message, title, options) => {
  if (typeof title === 'object') {
    options = title;
    title = '';
  } else if (title === undefined) {
    title = '';
  }
  return MessageBox(merge({
    title: title,
    message: message,
    $type: 'confirm',
    showCancelButton: true
  }, options));
};

textareaStyle() {
        return merge({}, this.textareaCalcStyle, { resize: this.resize });
      },
      inputSize() {

MessageBox.alert = (message, title, options) => {
  if (typeof title === 'object') {
    options = title;
    title = '';
  } else if (title === undefined) {
    title = '';
  }
  return MessageBox(merge({
    title: title,
    message: message,
    $type: 'alert',
    closeOnPressEscape: false,
    closeOnClickModal: false
  }, options));
};

insertChild(child, index, batch) {
    if (!child) throw new Error('insertChild error: child is required.');

    if (!(child instanceof Node)) {
      if (!batch) {
        const children = this.getChildren(true);
        if (children.indexOf(child.data) === -1) {
          if (typeof index === 'undefined' || index < 0) {
            children.push(child.data);
          } else {
            children.splice(index, 0, child.data);
          }
        }
      }
      objectAssign(child, {
        parent: this,
        store: this.store
      });
      child = new Node(child);
    }

    child.level = this.level + 1;

    if (typeof index === 'undefined' || index < 0) {
      this.childNodes.push(child);
    } else {
      this.childNodes.splice(index, 0, child);
    }

    this.updateLeafState();
  }

config() {
      return merge({ ...DefaultProps }, this.props || {});
    },
    multiple() {

const getDefaultColumn = function(type, options) {
  const column = {};

  objectAssign(column, defaults[type || "default"]);

  for (let name in options) {
    if (options.hasOwnProperty(name)) {
      const value = options[name];
      if (typeof value !== "undefined") {
        column[name] = value;
      }
    }
  }

  if (!column.minWidth) {
    column.minWidth = 80;
  }

  column.realWidth = column.width === undefined ? column.minWidth : column.width;