old_contents: const React = require('react');
  const classNames = require('classnames');
  
  const Link = React.createClass({
      propTypes: {
          href:       React.PropTypes.string,
          className:  React.PropTypes.string,
          children:   React.PropTypes.node,
          muted:      React.PropTypes.bool,
          underlined: React.PropTypes.bool,
          onClick:    React.PropTypes.func
      },
  
      getDefaultProps: function() {
          return {
              href: '#'
          };
      },
  
      onClick: function(e) {
          let { onClick } = this.props;
  
          if (onClick) {
              e.preventDefault();
              onClick(e);
          }
      },
  
      render: function() {
          let { href, className, children, muted, underlined, ...props } = this.props;
  
          className = classNames(className, {
              'muted-link':      muted,
              'underlined-link': underlined
          });
  
          return (
              <a
                  className={className}
                  href={href}
                  onClick={this.onClick}
                  {...props}
              >{children}</a>
          );
      }
  });
  
  module.exports = Link;
  
new_contents: const React = require('react');
  const classNames = require('classnames');
  
  const Link = React.createClass({
      propTypes: {
          href:       React.PropTypes.string,
          className:  React.PropTypes.string,
          children:   React.PropTypes.node,
          muted:      React.PropTypes.bool,
          underlined: React.PropTypes.bool,
          onClick:    React.PropTypes.func
      },
  
      getDefaultProps: function() {
          return {
              href: '#'
          };
      },
  
      onClick: function(e) {
          let { onClick } = this.props;
  
          if (onClick) {
              e.preventDefault();
              onClick(e);
          }
      },
  
      render: function() {
          let { href, className, children, muted, underlined, ...props } = this.props;
  
          className = classNames(className, {
              'muted-link':      muted,
              'underlined-link': underlined
          });
  
          return (
              <a
                  {...props}
                  className={className}
                  href={href}
                  onClick={this.onClick}
              >{children}</a>
          );
      }
  });
  
  module.exports = Link;
  
subject: Fix click on Link