public static class ByteStringParser.ParseResult<T>
implements scala.Product, scala.Serializable
param: result - parser can return some element for downstream or return None if no element was generated in this step
and parsing should immediately continue with the next step.
param: nextStep - next parser
param: acceptUpstreamFinish - if true - stream will complete when received onUpstreamFinish, if "false"
- onTruncation will be called