{"type":"example_label","message0":"%1 %2 %3","args0":[{"type":"field_label","text":"a label"},{"type":"input_dummy"},"and another label"]}
Blockly.Blocks['example_label']={init:function(){this.appendDummyInput().appendField(newBlockly.FieldLabel('a label'));this.appendDummyInput().appendField('and another label');}};