You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: http_headers.rb
    path of file: ./repos/sentry-ruby/sentry-raven/lib/raven/processor
    
    the code of the file until where you have to start completion: module Raven
  class Processor::HTTPHeaders < Processor
    DEFAULT_FIELDS = ["Auth
    
    def process_if_symbol_keys(data)
      return unless data[:request][:headers]

      data[:request][:headers].keys.select { |k| fields_re.match(k.to_s) }.each do |k|
        data[:request][:headers][k] = STRING_MASK
      end
    end