<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def genfirstvalues(cursor: Cursor, arraysize: int = 1000) \ -> Generator[Any, None, None]: """ Generate the first value in each row. Args: cursor: the cursor arraysize: split fetches into chunks of this many records Yields: the first value of each row """

    return (row[0] for row in genrows(cursor, arraysize))