// "True if among editable Text nodes that are effectively contained in
        // the active range, there are two that have distinct effective values.
        // Otherwise false."
        return collectAllEffectivelyContainedNodes(getActiveRange(), function(node) {
            return isEditable(node) && node.nodeType == Node.TEXT_NODE;
        }).map(function(node) {
            return getEffectiveValue(node, "fontname");
        }).filter(function(value, i, arr) {
            return arr.slice(0, i).indexOf(value) == -1;
        }).length >= 2;

        // vs.
        var nodes = collectAllEffectivelyContainedNodes(getActiveRange(), function(node) {
            return isEditable(node) && node.nodeType == Node.TEXT_NODE;
        });
        if (!nodes.length) {
            return false;
        }
        var value = getEffectiveValue(nodes[0], "fontname");
        for (var i = 1; i < nodes.length; i++) {
            if (getEffectiveValue(nodes[i], "fontname") != value) {
                return true;
            }
        }
        return false;