I'm working through a tutorial in Google Colaboratory, and the author has handily hidden some of the solutions cells. When you click the hidden cell, it expands and becomes visible. How can I hide the cells?
An example is in this tutorial: Creating and Manipulating Tensors.
None of the other answers worked for me. You can collapse cells by adding this to the top of the cell "#@title" and then double clicking on the white space that appears to the right of it.