old_contents: export function logger (message) {
  	if (console) {
  		console.log(`ScrollReveal: ${message}`); // eslint-disable-line no-console
  	}
  }
  
  /**
  * Sequential number generator for unique IDs.
  * @return {number}
  */
  export const nextUniqueId = (() => {
  	let uid = 0;
  	return () => uid++;
  })();
  
new_contents: export function logger (message) {
  	if (console) {
  		console.log(`ScrollReveal: ${message}`); // eslint-disable-line no-console
  	}
  }
  
  export const nextUniqueId = (() => {
  	let uid = 0;
  	return () => uid++;
  })();
  
subject: remove jsdoc block from nextUniqueId()