"qm-api-item-content"><div class="qm-api-description"><div class="qm-html-paragraph">A function for rendering the top left cell (the division between row headers and column headers) </div><div class="qm-html-paragraph">By default this function does not have a value and will be rendered as an empty cell. </div></div><div class="qm-api-group qm-api-arg-group"><div class="qm-api-group-header qm-api-arg-group-header qm-header-font">Arguments</div><div class="qm-api-item qm-api-javascript-arg qm-api-collapsible"