  /**
   * @dev Grants a role to an account by updating the account's status.
   *      Can only be called by an approved role provider.
   *
   *      If the account has an existing credential, it can only be updated if:
   *      - the previous credential's provider is no longer supported, OR
   *      - the caller is the previous role provider, OR
   *      - the new expiry is later than the current expiry
   */
  function grantRole(address account, uint32 roleGrantedTimestamp) external {
    RoleProvider callingProvider = _roleProviders[msg.sender];

    if (callingProvider.isNull()) revert ProviderNotFound();

    _grantRole(callingProvider, account, roleGrantedTimestamp);
  }
