# File lib/aws/s3/request.rb, line 157 def canonicalized_headers x_amz = headers.select{|name, value| name.to_s =~ /^x-amz-/i } x_amz = x_amz.collect{|name, value| [name.downcase, value] } x_amz = x_amz.sort_by{|name, value| name } x_amz = x_amz.collect{|name, value| "#{name}:#{value}" }.join("\n") x_amz == '' ? nil : x_amz end