def get(key, expected_checksum=nil)
      request_data = {:key => key}.to_json
      request = prepare_request :GET, request_data
      response = execute_request(request)
      verify_checksum(response["data"], expected_checksum) unless expected_checksum.nil?
      Response.new(response)
    end
def get(key, expected_checksum=nil)
      request_data = {:key => key}.to_json
      request = prepare_request :GET, request_data
      response = execute_request(request)
      verify_checksum(response["data"], expected_checksum) unless expected_checksum.nil?
      Response.new(response)
    end
Recover data stored at a given SAM key

 @param [String] key of the value to acess
 @return [Response] response object holding the file and some metadata

 @raise [NSISam::Errors::Client::KeyNotFoundError] when the key doesn't exists
 @raise [NSISam::Errors::Client::AuthenticationError] when user and password doesn't match

 @example
   nsisam.get("some key")