Change assert!s for debug_assert!s

[MauroToscano]

Some functions should return a Resultinstead of using an assert because doing the latter would panic in runtime.

In general, if you don't have any choice but to panic it is better to describe the cases in which that function would panic and why in the documentation.

For this issue, we just want to replace these assertions with debug assertions. We'll address the Result in another issue.

An example would be this.

[josepchetrit12]

Can you write a short description? Thank you

[ilitteri]

Can you write a short description? Thank you

Description added!

[josepchetrit12]

Can I take it?

[ilitteri]

Can I take it?

Sorry for the delay, sure you can take it!