Function ZL_Output_setIntMetadata 

pub unsafe extern "C" fn ZL_Output_setIntMetadata(
    output: *mut ZL_Output,
    key: c_int,
    value: c_int,
) -> ZL_Report

@brief Sets integer metadata with the key @p key and value @p value on the stream.

It is only valid to call ZL_Data_setIntMetadata() with the same @p key once. Subsequent calls with the same @p key will return an error.

@param key Metdata key @param value Metadata value

@returns Success or an error. This function will fail due to repeated calls with the same @p key, or upon running out of space for the metadata.

@note In this proposed design, Int Metadata are set one by one. Another possible design could follow the IntParams model, where all parameters must be set all-at-once, and be provided as a single vector of IntParams structures.

@note The set value is an int, hence it’s not suitable to store “large” values, like 64-bit ULL.