class Foo { someMethod ( arr ) { arr . forEach ( x => this . log ( x ) ) ; } log ( value ) { console . log ( value ) ; } } const help = ( ) => console . log ( 'Help me, please!' ) ; help ( ) ; let React ; class ReactElement { doAThing ( ) { } render ( ) { return React . createElement ( 'div' , { onClick : ( ) => this . doAThing ( ) } ) ; } }