FuncName given a runtime function spec returns a short function name in format `<package name>.<function name>` or if the function has a receiver in format `<package name>.(<receiver>).<function name>`.

GetLastFrame returns Caller information on the first frame in the stack trace.

GoRoutineID returns the current goroutine id.

New creates a new CallStack struct from current stack minus 'skip' number of frames.

CallStack represents a stack of program counters.