images/src/main/java/com/stanfy/enroscar/images/MarkableInputStream.java
public long savePosition(int readLimit) {
    long offsetLimit = offset + readLimit;
    if (limit < offsetLimit) {
      setLimit(offsetLimit);
    }
    return offset;
  }
public long savePosition(int readLimit) {
    long offsetLimit = offset + readLimit;
    if (limit < offsetLimit) {
      setLimit(offsetLimit);
    }
    return offset;
  }
Returns an opaque token representing the current position in the stream.
Call {@link #reset(long)} to return to this position in the stream later.
It is an error to call {@link #reset(long)} after consuming more than
{@code readLimit} bytes from this stream.