BiagioMkr:
I have updated [...] the library name.
You indeed did. But the wrong way around... A library name should not have a name that is very generic. Because you can't have two libraries with the same name and the changes are pretty big somebody else made the same mistake and gave a library a generic name as Led. Or pick a more creative name or prefix it, like Biagiom-Led.
BiagioMkr:
Regarding your comment about the use of SERIAL macro, if you look at the Led.h file you can see that if SERIAL_DEBUG is not defined, the SERIAL macro and the methods of Led class that use Serial communication are not defined so that is not an error.
I saw the define etc. But what I missed is that you only used the SERIAL macro in #ifdef blocks. I was just looking at it in GitHub, not an editor. As long as you do that it will indeed work. I thought the SERIAL.print() where just in the normal code. Then it would not work of course but my method would.
But not to be rude, a library that uses delay() to blink a led (ignoring the overhead) is not very useful in my opinion.
PS What you call pull(Type) has nothing to do with pulling. It's the driveType High side or low side switching.
PSS Like the Doxygen documentation