How to use the utilities.joinClasses function in utilities

render() {
    // Attach the formGroupId to allow automatic focus when a label is clicked
    const childrenWithProps = React.Children.map(this.props.children,
      child => {
        if (React.isValidElement(child) && isFunc(child.type)) {
          return React.cloneElement(child, { formGroupId: this.formGroupId });
        }
        return child;
      }
    );
    return <div>{childrenWithProps}</div>;
  }
}

render() {
    return (
      <div>
        
        
          {this.props.children}
        
      </div>
    );
  }
}

export const SectionHeader = (props) => (
  <div>{props.children}</div>
);

export const PropertyGridHeader = (props) => (
  <div>{props.children}</div>
);

export const BtnToolbar = (props) => (
  <div>{props.children}</div>
);

export const Select = ({ className, onChange, name, ...props }) => {
  return ;
};

export const Cell = ({ className, children }) => (
  <div>
    <div>
      { children }
    </div>
  </div>
);

export const Hyperlink = (props) => {
  const { children, className, href } = props;

  if (!href) return null;
  return (
    <a>
      {children}
    </a>
  );
};

export const ErrorMsg = (props) => {
  const { children, className } = props;
  return (
    <div>
      <svg path="{svgs.error}"></svg>
      { children }
    </div>
  );
};

export const Panel = ({ className, children }) => (
  <div>
    { children }
  </div>
);