code: def parseFromDelimitedString(obj, buf, offset=0):
      
      size, pos = _DecodeVarint(buf, offset)
      obj.ParseFromString(buf[offset+pos:offset+pos+size])
      return pos+size
docs: Stanford CoreNLP uses the Java "writeDelimitedTo" function, which
      writes the size (and offset) of the buffer before writing the object.
      This function handles parsing this message starting from offset 0.
  
      @returns how many bytes of @buf were consumed.