module Magick

def formats
  @formats ||= init_formats
  if block_given?
    @formats.each { |k, v| yield k, v }
    self
  else
    @formats
  end
end

def trace_proc=(p)
  if @trace_proc.nil? && !p.nil? && !@exit_block_set_up
    at_exit { @trace_proc = nil }
    @exit_block_set_up = true
  end
  @trace_proc = p
end