<?php
var_dump(version_compare('3.7.5', '3.7.0', 'ge')); // true, OK
var_dump(version_compare('3.7.5', '3.7.0', ' ')); // null, should throw invalid argument exception at best
var_dump(version_compare('3.7.5', '3.7.0', ' ge')); // null, should throw invalid argument exception at best
var_dump(version_compare('3.7.5', '3.7.0', 'ge ')); // null, should throw invalid argument exception at best
var_dump(version_compare('3.7.5', '3.7.0', 'invalid')); // null, should throw invalid argument exception at best