function getTextNodeID(textNode) {
        var childIndex = textNode.parent.children.indexOf(textNode);
        if (childIndex === 0) {
            return textNode.parent.tagID + ".0";
        }
        return textNode.parent.children[childIndex - 1].tagID + "t";
    }
@private

Generates a synthetic ID for text nodes. These IDs are only used
for convenience when reading a SimpleDOM that is dumped to the console.

@param {Object} textNode new node for which we are generating an ID
@return {string} ID for the node