code: def _parse_one_event(self):
          
          # WVA includes \r\n between messages which the parser doesn't like, so we
          # throw away any data before a opening brace
          try:
              open_brace_idx = self._buf.index('{')
          except ValueError:
              self._buf = six.u('')  # no brace found
          else:
              if open_brace_idx > 0:
                  self._buf = self._buf[open_brace_idx:]
  
          try:
              event, idx = self._decoder.raw_decode(self._buf)
              self._buf = self._buf[idx:]
              return event
          except ValueError:
              return None
docs: Parse the stream buffer and return either a single event or None