async selectAllRows() {
        const headCheckbox = await $(this.rootElement)
            .$('thead')
            .$(HEAD_CHECKBOX_INPUT_SELECTOR);
        if (
            !(await headCheckbox.isSelected()) &&
            !(await headCheckbox.getAttribute('indeterminate'))
        ) {
            await $(this.rootElement)
                .$('thead')
                .$(HEAD_CHECKBOX_LABEL_SELECTOR)
                .click();
        }
    }
Clicks the head checkbox to select the maximum selectable rows.
@method