code: func (b *LookAheadBuffer) PeekAll() ([]byte, error) {
  	return b.Peek(len(b.buffer))
  }
docs: // PeekAll returns the entire look ahead buffer with all bytes populated.
  // If the look ahead buffer does not already hold enough bytes, it will read
  // from the underlying reader to populate the rest.  NOTE: the returned slice
  // is not a copy of the raw buffer.