isExisting
Returns true if element exists in the DOM
Usage
$(selector).isExisting()
Examples
<div id="notDisplayed" style="display: none"></div>
<div id="notVisible" style="visibility: hidden"></div>
<div id="notInViewport" style="position:absolute; left: 9999999"></div>
<div id="zeroOpacity" style="opacity: 0"></div>
it('should detect if elements are existing', () => {
    let elem = $('#someRandomNonExistingElement')
    let isExisting = elem.isExisting()
    console.log(isExisting); // outputs: false
    elem = $('#notDisplayed')
    isExisting = elem.isExisting()
    console.log(isExisting); // outputs: true
    elem = $('#notVisible')
    isExisting = elem.isExisting()
    console.log(isExisting); // outputs: true
    elem = $('#notInViewport')
    isExisting = elem.isExisting()
    console.log(isExisting); // outputs: true
    elem = $('#zeroOpacity')
    isExisting = elem.isExisting()
    console.log(isExisting); // outputs: true
});