code: function createButtonClassName(props) {
    return createClassName(
      props.noDefaultClassName ? null : 'button',
      props.className,
      props.size,
      props.color,
      {
        'hollow': props.isHollow,
        'clear': props.isClear,
        'expanded': props.isExpanded,
        'disabled': props.isDisabled,
        'dropdown': props.isDropdown,
        'arrow-only': props.isArrowOnly
      },
      generalClassNames(props)
    );
  }
docs: Creates button class name from the given properties.
  
  @param {Object} props
  @returns {string}