Table header not shown with pgfplotstable in Tikzpicture environment

Question

I'm trying to get pgfplotstable to show the header of the columns in my csv file as well. It seems like this should be the default behaviour, and I can't seem to find anyone else having this problem. Here is the MWE:

\documentclass{article}
\usepackage{pgfplotstable}

% The input .csv file.
\begin{filecontents*}{TestPGFPlotsTable.csv}
A,B,C,D
1,5,9,13
2,6,10,14
3,7,11,15
4,8,12,16
\end{filecontents*}

% To add a line above and below the header and table. 
% Using hline instead of booktabs to make MWE
\pgfplotstableset{ 
 every head row/.style={before row=\hline,after row=\hline},
 every last row/.style={after row=\hline}
}

\begin{document}

    % Where is the header??
    \begin{tikzpicture}
        \pgfplotstableset{
          col sep=comma,
        }
        \pgfplotstabletypeset[]{TestPGFPlotsTable.csv}

    \end{tikzpicture}

\end{document}

And here is what the result looks like:

And the result I want to get.

Answer 1

Is there a reason why the \pgfplotstabletypeset is within a tikzpicture environment?

\documentclass{article}
\usepackage{pgfplotstable}
\usepackage{caption}

% The input .csv file.
\begin{filecontents*}{TestPGFPlotsTable.csv}
A,B,C,D
1,5,9,13
2,6,10,14
3,7,11,15
4,8,12,16
\end{filecontents*}

% To add a line above and below the header and table. 
% Using hline instead of booktabs to make MWE
\pgfplotstableset{
 every head row/.style={before row=\hline,after row=\hline},
 every last row/.style={after row=\hline},
}

\begin{document}

\pgfplotstableset{  
    col sep=comma
    }
\pgfplotstabletypeset{TestPGFPlotsTable.csv}

\begin{center}
\pgfplotstabletypeset{TestPGFPlotsTable.csv}
\end{center}

\begin{table}[htb]
    \centering
    \caption{My caption}
    \pgfplotstabletypeset{TestPGFPlotsTable.csv}
\end{table}
\end{document}