\documentclass[a4paper]{article}

\usepackage{pgfplots}
\usepackage{pgfplots.assert}

\pgfplotsset{compat=1.7}

\begin{document}

\makeatletter


% Verify a line in X direction against several surfs:
\pgfplotspointonorientedsurfaceabmatchaxisline@ v22:ab2\pgfplots@EOI%
\pgfplotsassertequalstok{2}{\pgfplots@loc@TMPa}{}

\pgfplotspointonorientedsurfaceabmatchaxisline@ v22:a2b\pgfplots@EOI%
\pgfplotsassertequalstok{2}{\pgfplots@loc@TMPa}{}

\pgfplotspointonorientedsurfaceabmatchaxisline@ v22:2ab\pgfplots@EOI%
\pgfplotsassertequalstok{}{\pgfplots@loc@TMPa}{}



% Verify a line in Y direction against several surfs:
\pgfplotspointonorientedsurfaceabmatchaxisline@ 2v2:a2b\pgfplots@EOI%
\pgfplotsassertequalstok{}{\pgfplots@loc@TMPa}{}

% Verify a line in Z direction against several surfs:
\pgfplotspointonorientedsurfaceabmatchaxisline@ 22v:ab2\pgfplots@EOI%
\pgfplotsassertequalstok{}{\pgfplots@loc@TMPa}{}

\pgfplotspointonorientedsurfaceabmatchaxisline@ 22v:a2b\pgfplots@EOI%
\pgfplotsassertequalstok{v}{\pgfplots@loc@TMPa}{}
\end{document}
