guavasupport/src/main/java/com/streamsets/pipeline/lib/io/fileref/AbstractWrapperStream.java
@Override
  public int read(ByteBuffer dst) throws IOException {
    checkState(ReadableByteChannel.class);
    return  ((ReadableByteChannel)stream).read(dst);
  }
@Override
  public int read(ByteBuffer dst) throws IOException {
    checkState(ReadableByteChannel.class);
    return  ((ReadableByteChannel)stream).read(dst);
  }
@ Override public int read ( ByteBuffer dst ) throws IOException { checkState ( ReadableByteChannel . class ) ; return ( ( ReadableByteChannel ) stream ) . read ( dst ) ; }
ReadableByteChannel
ReadableByteChannel