code: function getButton(opts) {
  
    var type = opts.type || 'default';
  
    var className = {
      'btn': true,
      'btn-block': opts.block,
      'active': opts.active
    };
    className['btn-' + type] = true;
    if (opts.size) {
      className['btn-' + opts.size] = true;
    }
    if (opts.className) {
      className[opts.className] = true;
    }
  
    var events = opts.events || {
      click: opts.click
    };
  
    return {
      tag: 'button',
      attrs: {
        type: 'button',
        disabled: opts.disabled,
        className: className,
        autoFocus: opts.autoFocus
      },
      events: events,
      children: opts.label,
      key: opts.key
    }
  }
docs: /*
  
  Example:
  
  {
  type: 'primary',
  block: true,
  active: true,
  size: 'lg',
  disabled: true,
  autoFocus: true,
  events: {
  ...
  }
  }