+ * One of the following properties is mandatory
+ *
+ * | %Property Name | Type |
+ * |------------------- |-------------------|
+ * | url | STRING |
+ * | urls | ARRAY of STRING |
+ *
+ * The remaining properties are optional
+ * | pixelArea | VECTOR4 |
+ * | wrapModeU | INTEGER OR STRING |
+ * | wrapModeV | INTEGER OR STRING |
+ * | cacheSize | INTEGER |
+ * | batchSize | INTEGER |
+ * | frameDelay | INTEGER |
+ *
+ * pixelArea is a rectangular area.
+ * In its Vector4 value, the first two elements indicate the top-left position of the area,
+ * and the last two elements are the area width and height respectively.
+ * If not specified, the default value is [0.0, 0.0, 1.0, 1.0], i.e. the entire area of the image.