class Pry::Command::Cat::ExceptionFormatter

def backtrace_level
  @backtrace_level ||=
    begin
      bl =
        if opts[:ex].nil?
          ex.bt_index
        else
          ex.bt_index = absolute_index_number(opts[:ex], ex.backtrace.size)
        end
      increment_backtrace_level
      bl
    end
end