class WebMock::HttpLibAdapters::CurbAdapter

def self.parse_header_string(header_string)

http://github.com/toland/patron/blob/master/lib/patron/response.rb
Borrowed from Patron:
def self.parse_header_string(header_string)
  status, headers = nil, {}
  header_string.split(/\r\n/).each do |header|
    if header =~ %r{\AHTTP/(1\.[01]|2) (\d{3})\s*(.*)}
      status = $3
    else
      parts = header.split(':', 2)
      unless parts.empty?
        parts[1].strip! unless parts[1].nil?
        if headers.has_key?(parts[0])
          headers[parts[0]] = [headers[parts[0]]] unless headers[parts[0]].kind_of? Array
          headers[parts[0]] << parts[1]
        else
          headers[parts[0]] = parts[1]
        end
      end
    end
  end
  return status, headers
end