I have defined an environment as follows. I would like to have a modification where, it does not add white vertical space if no arguments are provided.
\documentclass[10]{article}
\usepackage[a4paper, margin=1in]{geometry}
\usepackage{tabu}
\usepackage{enumitem}
\setlist{leftmargin=5mm, noitemsep, topsep=-1\parskip}
\newenvironment{cvsection}[1]{
\vspace{3pt}
\hspace{3pt}{\scriptsize{\textbf{#1}}}
\vspace{2pt}
\hrule
}
\newenvironment{cvsubsection}[3]{
\vspace{-8pt}
\begin{center}
\begin{tabu} to 1\textwidth { X[l,m] X[c,m] X[r,m] }
\textbf{\small #1} & \textbf{\small #2} & \textbf{\small #3} \\
\end{tabu}
\end{center}
}
\begin{document}
\begin{cvsection}{LANGUAGES \& TECHNOLOGIES}
\begin{cvsubsection}{}{}{}
\begin{itemize}
\item C++; C; Java; Objective-C; C\#.NET; SQL; JavaScript; XSLT; XML (XSD) Schema
\item Visual Studio; Microsoft SQL Server; Eclipse; XCode; Interface Builder
\end{itemize}
\end{cvsubsection}
\end{cvsection}
\end{document}
The above gives the following. I would like to remove the white spacing marked in red, if I don't provide arguments to my cvsubsection. If I do provide arguments, it should work as already defined above.
Desired output with relevant code (NOTE code is just to show the output what I want. I still want to pass empty arguments to my cvsubsection)
\begin{cvsection}{LANGUAGES \& TECHNOLOGIES}
% \begin{cvsubsection}{}{}{}
\vspace{4pt}
\begin{itemize}
\item C++; C; Java; Objective-C; C\#.NET; SQL; JavaScript; XSLT; XML (XSD) Schema
\item Visual Studio; Microsoft SQL Server; Eclipse; XCode; Interface Builder
\end{itemize}
% \end{cvsubsection}
\end{cvsection}


