Windows Nurikabe Insructions

Rules: The objective is to divide the grid into shaded and unshaded cells, subject to the following rules:

1. Each numbered cell is an island cell, the number in it is the number of cells in that island.
2. Each island contains exactly one numbered cell.
3. There must be only one stream, which is not allowed to contain "pools", i.e. 2x2 areas of shaded cells.
4. The pattern of shaded and unshaded cells in the solid box must be the inverse of the pattern of shaded and unshaded cells in the dashed box of the same colour. The orientation of which stays the same.