# File lib/rr/deprecations.rb, line 69
    def self.show_warning(msg, options = {})
      start_backtrace_at_frame = options.fetch(:start_backtrace_at_frame, 2)
      backtrace = caller(start_backtrace_at_frame)

      lines = []
      lines << ('-' * 80)
      lines << 'Warning from RR:'
      lines.concat msg.split(/\n/).map {|l| "  #{l}" }
      lines << ""
      lines << "Called from:"
      lines.concat backtrace[0..2].map {|l| " - #{l}" }
      lines << ('-' * 80)

      Kernel.warn lines.join("\n")
    end