Nonogram no 1

I created this puzzle by trial and error in a table in a Google Doc. It was tested on Dmytro Fedoriaka's site.

The squares in the 10 x 10 grid below must be either left empty or shaded black.

The numbers 4, 1 and 2 above column 1 mean that it contains 4 contiguous shaded squares, possibly preceded by one or more blank squares.

Below this there are one or more blank squares followed by 1 shaded square.

Below this there are one or more blank squares followed by 2 contiguous shaded squares.

There may (or may not) be blank squares below this.

The numbers 1 and 7 above column 3 mean that it contains 1 shaded square, possibly preceded by one or more blank squares.

Below this there are one or more blank squares followed by 7 contiguous shaded squares.

There may (or may not) be blank squares below this.

The numbers to the left of each row control the shading in that row in a similar fashion:

 See answer