import jnr.ffi.annotations...
* Clear (?no usages), In, Out
* Pinned - lock/unlock JVM memory instead of copying to/from native-memory
* Transient
    This means it can be backed by a temporarily allocated native memory block,
 and after the method call, the native memory can be freed again.
* NulTerminate - for strings

Pinned (?No check for this annotation):
https://github.com/jnr/jnr-ffi/blob/master/src/test/java/jnr/ffi/struct/UTF8StringFieldTest.java