@Override
    public int read() throws IOException {
        //noinspection Convert2MethodRef
        return read(buffer -> readFromBuffer(buffer));
    }
Closes this {@link InputStream} and releases any system resources associated with the stream.
Sets EOS, if it has not been set yet. Drains all the allocated buffers.
core/src/main/java/com/linecorp/armeria/internal/common/stream/ByteBufsInputStream.java