What is the type of child

What is the type of a child?

renderChildren(): void {  const {children} = this.props;  const childrenArray = React.Children.map(children, (child) => {    return this.renderChild(child);  })  ...}renderChild = (child: whatAmI): void => {  ...}

Digging in the code it looks like it is ReactNode but I did not find an official doc for react-native on this, and I would like to know.