text: import React, { PureComponent } from 'react';
  import PropTypes from 'prop-types';
  import cn from 'classnames';
  
  export default class Message extends PureComponent {
    static propTypes = {
      active: PropTypes.bool,
      className: PropTypes.string,
      children: PropTypes.node,
    };
  
    render() {
      const { active, children, className } = this.props;
  
      if (!children) {
        return null;
      }
  
      return (
        <p
          aria-hidden={!active}
          className={cn(
            'md-text-field-message',
            `md-text-field-message--${active ? '' : 'in'}active`,
            className
          )}
        >
          {children}
        </p>
      );
    }
  }
  