/**
 * Check and return true if an object is type of string
 */ export function isString ( obj ) { return typeof obj === "string" ; } /**
 * Check and return true if an object not undefined or null
 */ export function isPresent ( obj ) { return obj !== undefined && obj !== null ; } /**
 * Check and return true if an object is type of Function
 */ export function isFunction ( obj ) { return typeof obj === "function" ; } /**
 * Create Image element with specified url string
 */ export function createImage ( src ) { let img = new HTMLImageElement ( ) ; img . src = src ; return img ; } /**
 * Call the function
 */ export function callFun ( fun ) { return fun ( ) ; }