/guava/guava/src/com/google/common/io/ByteSource.java
Optional<Long> size = sizeIfKnown( ) ;Optional<Long> sizeIfKnown = sizeIfKnown( ) ;
Optional<Long> sizeIfKnown = sizeIfKnown ( ) ;
: new BufferedInputStream(in); } public ByteSource slice(long offset, long length) { return new SlicedByteSource(offset, length); } public boolean isEmpty() throws IOException { <extra_id_0> if (sizeIfKnown.isPresent()) { return sizeIfKnown.get() == 0L; } Closer closer = Closer.create(); try { InputStream in = closer.register(openStream());