public function validate( $variableSet, $nsMgr )
	{
		if ( isset( $this->test ) && ! empty( $this->test ) )
		{
			try
			{
				$expression = XPath2Expression::Compile( $this->test, $nsMgr );
				$this->testXPath2Expression = $expression;
			}
			catch ( Exception $ex )
			{
				\XBRL_Log::getInstance()->valueassertion_validation( "Value assertion", "Failed to compile test expression",
					array(
						'test expression' => $this->test,
						'error' => $ex instanceof XPath2Exception ? $ex->ErrorCode : get_class( $ex ),
						'reason' => $ex->getMessage()
					)
				);

				return false;
			}

		}

		return true;
	}