\FloatBarrier
\begin{table}[!htbp]
\begin{center}
\caption{A table example.}
\label{tab:a-table-example}
\vspace*{5pt}
\begin{tabular}{||m{3cm}|D{3cm}|F{3cm}|G{3cm}||N}
\hline
justified \dummytext & left-aligned \dummytext & centered \dummytext & right-aligned \dummytext & \\
\hline
This is an example & 2 & 3 & 4 & \\
\hline
Single cell & \multicolumn{3}{c||}{A multi-column cell} & \\
\hline
\multirow{2}[1]{*}{A multi-row cell} & A simple & ... & ... & \\
& example & ... & ... & \\
\hline
\end{tabular}
\end{center}
\end{table}
\FloatBarrier
