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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 _avro_rows(block, avro_schema):
 """Parse all rows in a stream block. Args: block ( \ ~google.cloud.bigquery_storage_v1beta1.types.ReadRowsResponse \ ):
 A block containing Avro bytes to parse into rows. avro_schema (fastavro.schema):
 A parsed Avro schema, used to deserialized the bytes in the block. Returns: Iterable[Mapping]: A sequence of rows, represented as dictionaries. """

    blockio = six.BytesIO(block.avro_rows.serialized_binary_rows)
    while True:
        # Loop in a while loop because schemaless_reader can only read
        # a single record.
        try:
            # TODO: Parse DATETIME into datetime.datetime (no timezone),
            #       instead of as a string.
            yield fastavro.schemaless_reader(blockio, avro_schema)
        except StopIteration:
            break