<style>
div {
    float:left;
    display: block;
    margin: 10px;
    padding:0px;
    width: 50px;
    height: 50px;
    background: green;
}
br {
    clear: left;
}
</style>
<!-- 
    This test checks that a null filter will not affect the rendering of the box at all.
    There should be 13 green boxes on screen. 
-->
<div style="filter: blur(0)"></div>
<div style="filter: brightness(1)"></div>
<div style="filter: invert(0)"></div>
<div style="filter: contrast(1)"></div>

<br />

<div style="filter: drop-shadow(0px 0px 0px rgba(0, 0, 0, 0))"></div>
<div style="filter: grayscale(0)"></div>
<div style="filter: hue-rotate(0)"></div>
<div style="filter: invert(0)"></div>

<br />

<div style="filter: opacity(1)"></div>
<div style="filter: saturate(1)"></div>
<div style="filter: sepia(0)"></div>
<div style="filter: blur(0) grayscale(0)"></div>

<br />

<div style="filter: grayscale(0) blur(0)"></div>