code: function areValidConstants(receivedConstants) {
    return typeof(receivedConstants) === 'object' &&
        typeof(receivedConstants.logEventTypes) === 'object' &&
        typeof(receivedConstants.clientInfo) === 'object' &&
        typeof(receivedConstants.logEventPhase) === 'object' &&
        typeof(receivedConstants.logSourceType) === 'object' &&
        typeof(receivedConstants.loadFlag) === 'object' &&
        typeof(receivedConstants.netError) === 'object' &&
        typeof(receivedConstants.addressFamily) === 'object' &&
        isNetLogNumber(receivedConstants.timeTickOffset) &&
        typeof(receivedConstants.logFormatVersion) === 'number';
  }
docs: Returns true if it's given a valid-looking constants object.
  @param {Object} receivedConstants The received map of constants.
  @return {boolean} True if the |receivedConstants| object appears valid.