 of 2-element arrays. The first entry in each of these arrays is the value, the second entry is also the value. This is just how the ES6 spec currently says to do things, presumably to stay consistent with the Map collection. </div></div><div class="qm-api-group qm-api-returns-group"><div class="qm-api-group-header qm-api-returns-group-header qm-header-font">Returns</div><div class="qm-api-item qm-api-javascript-returns qm-api-collapsible"><div class="qm-api-collapsible-heading"><div class="qm-api-collapsib