function normalize( value, len, strict ) {
	// Case: null
	if ( value === null ) {
		// Create a slice with default extents and a default increment:
		return new Slice( 0, len, 1 );
	}
	// Case: integer
	if ( typeof value === 'number' ) {
		return int2slice( value, len, strict );
	}
	// Case: slice
	return normalizeSlice( value, len, strict );
}
Normalizes an individual MultiSlice element.

@private
@param {(Slice|integer|null)} value - input slice
@param {NonNegativeInteger} len - maximum number of elements which are allowed in a slice
@param {boolean} strict - boolean indicating whether to enforce strict bounds checking
@returns {Slice} slice object