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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def validate_request_row_key(self, request):
        '''
        Validates that all requests have the different RowKey and adds RowKey
        to existing RowKey list.

        request:
            the request to insert, update or delete entity
        '''
        if self.batch_row_keys:
            if self.get_request_row_key(request) in self.batch_row_keys:
                raise AzureBatchValidationError(_ERROR_DUPLICATE_ROW_KEY_IN_BATCH)
        else:
            self.batch_row_keys.append(self.get_request_row_key(request))