checks whether this handle has been closed . concode_field_sep AtomicIntegerFieldUpdater<AbstractCloseableHandle> CLOSER concode_elem_sep Closeable toClose concode_elem_sep int isClosed concode_elem_sep long serialVersionUID concode_field_sep void ensureNotClosed concode_elem_sep void close concode_elem_sep void registerCloseable
boolean function ( ) { return isClosed != 0 ; }