fails:Thread#backtrace_locations without argument is the same as showing all locations with 0..-1
fails:Thread#backtrace_locations the first location reports the call to #backtrace_locations
fails:Thread#backtrace_locations can be called with a range whose end is negative
fails:Thread#backtrace_locations returns nil if omitting more locations than available
fails:Thread#backtrace_locations can be called with `nil` length
