getInputType( builder ) {

		return this.getNodeType( builder );

	}
Returns the input type of the node which is by default the node type. Derived modules
might overwrite this method and use a fixed type or compute one analytically.

A typical example for different input and node types are textures. The input type of a
normal RGBA texture is `texture` whereas its node type is `vec4`.

@param {NodeBuilder} builder - The current node builder.
@return {string} The input type.