Function duckdb_appender_clear 

pub unsafe extern "C" fn duckdb_appender_clear(
    appender: duckdb_appender,
) -> duckdb_state

Clears all buffered data from the appender without flushing it to the table. This discards any data that has been appended but not yet written. The appender can continue to be used after clearing.

@param appender The appender to clear. @return DuckDBSuccess on success or DuckDBError on failure.