In order to implement File, your type must inherit fromGObject.

• GArrowBufferInputStream
• GArrowBufferOutputStream
• GArrowCompressedInputStream
• GArrowCompressedOutputStream
• GArrowFileInputStream
• GArrowFileOutputStream
• GArrowGIOInputStream
• GArrowGIOOutputStream
• GArrowInputStream
• GArrowMemoryMappedInputStream
• GArrowOutputStream
• GArrowSeekableInputStream

struct ArrowFileInterface {  /* no available fields */}