Stream::write( $string )

163    public function write($string): int164    {165        if (!isset($this->stream)) {166            throw new \RuntimeException('Stream is detached');167        }168        if (!$this->writable) {169            throw new \RuntimeException('Cannot write to a non-writable stream');170        }171        // We can't know the size after writing anything172        $this->size = null;173        if (\false === $result = @\fwrite($this->stream, $string)) {174            throw new \RuntimeException('Unable to write to stream: ' . (\error_get_last()['message'] ?? ''));175        }176        return $result;177    }