# File lib/innodb/util/buffer_cursor.rb, line 90
  def trace_with(arg=nil)
    if arg.nil?
      @trace_proc = nil
    elsif arg.class == Proc
      @trace_proc = arg
    elsif arg.class == Symbol
      @trace_proc = lambda { |cursor, position, bytes, name| self.send(arg, cursor, position, bytes, name) }
    else
      raise "Don't know how to trace with #{arg}"
    end
    self
  end