latex comment over equal sign code example

Example 1: tex write above

$\overset{\mathrm{def}}{=}$

Example 2: text over equal latex

\documentclass[preview]{standalone}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\newcommand{\approxtext}[1]{\ensuremath{\stackrel{\text{#1}}{\approx}}}
\begin{document}
    $\displaystyle
        A \stackrel{\text{text}}{\approx} B
    $, 
    $\displaystyle
        A \approxtext{test} B
    $
\end{document}