code: function addTextLabel(root, node) {
    var domNode = root.append("text");
  
    var lines = processEscapeSequences(node.label).split("\n");
    for (var i = 0; i < lines.length; i++) {
      domNode.append("tspan")
        .attr("xml:space", "preserve")
        .attr("dy", "1em")
        .attr("x", "1")
        .text(lines[i]);
    }
  
    util.applyStyle(domNode, node.labelStyle);
  
    return domNode;
  }
docs: /*
  Attaches a text label to the specified root. Handles escape sequences.