"Merge" functions are used to provide a way to present different "layer merging" operations among different layers. There are some key points we want to highlight here for the "Merge" functions.

We designed all merge function as a "Factory" for layer merging operation. The factory returns a merged layer object with providing some proper parameters: a list of layer objects need to be merged and some configurations of the returned merged object.

The list should contain layers need to be merged. The provided layers need to match the shape requirements based on the corresponding merge function. For example, all layers for "Add" function should have the same shape.

The configurations is used to describe the generated merged layer object. The configurations include the basic settings and status about the merged layer object.