(mongodb >= 1.6.0)
MongoDB\Driver\Exception\RuntimeException::hasErrorLabel — Returns whether an error label is associated with an exception
$errorLabel): bool
   Returns whether the errorLabel has been set for this
   exception. Error labels are set by either the server or the driver to
   indicated specific situations on which you might want to decide on how you
   want to handle a specific exception. A common situation might be to find
   out whether you can safely retry a transaction that failed due to a
   transient error (like a networking issue, or a transaction conflict).
   Examples of error labels are TransientTransactionError
   and UnknownTransactionCommitResult.
  
errorLabelThe name of the errorLabel to test for.
   Whether the given errorLabel is associated with this
   exception.