Describe the bug
Only a few levels are printed in pretty mode. It's caused by broken _extend function, which ignores depth settings, therefore the hardcoded depth with value 2 is applied.

To Reproduce
Try to log an object with 3+ depth - only 3 levels are pretty printed, the deeper levels are represented with [object Object] string
https://codepen.io/jakubhruby/pen/OJYgzbR?editors=1111

Expected behavior
Full depth object is printed.

Screenshots

Here is the code which tries to assign opts (which includes dept: Infinite) to ctx, but it doesn't and ctx remains untouched. Below the default 2 is assigned to ctx.depth which limits output to three levels.