docs: function(parent, field, options) {  
    options = options || {};
    // Unique id for this node's generated method
    this.id = utils.generateId();
    // Link to parent node
    this.parent = parent;
    // The field related to this node
    this.field = field;
    // Any options
    this.options = options;
    // Just some metadata
    this.type = 'custom';
    // Custom context
    this.context = {};  
  }