--- /dev/null
+// This file:
+// - declares symbols that are provided outisde of dygraphs
+// - defines custom types used internally
+
+
+/**
+ * @typedef {function(
+ * (number|Date),
+ * number,
+ * function(string):*,
+ * (Dygraph|undefined)
+ * ):string}
+ */
+var AxisLabelFormatter;
+
+
+/**
+ * @typedef {function(number,function(string),Dygraph):string}
+ */
+var ValueFormatter;
+
+
+/**
+ * @typedef {Array.<Array.<string|number|Array.<number>>>}
+ */
+var DygraphDataArray;
+
+/**
+ * @constructor
+ */
+function GVizDataTable() {}