);
    }

    /**
     * Version of this code.
     * Best practice: define version strings to be easily compared using version_compare()
     * (http://php.net/manual/en/function.version-compare.php)
     * NOTE: You should manually make this match the SVN tag for your main plugin file 'Version' release and 'Stable tag' in readme.txt
     * @return string
     */
    public function getVersion() {
        return $this->getPluginHeaderValue( 'Version' );
    }

    /**
     * Useful when checking for upgrades, can tell if the currently installed version is earlier than the
     * newly installed code. This case indicates that an upgrade has been installed and this is the first time it
     * has been activated, so any upgrade actions should be taken.
     * @return bool true if the version saved in the options is earlier than the version declared in getVersion().
     * true indicates that new code is installed and this is the first time it is activated, so upgrade actions
     * should be taken. Assumes that version string comparable by version_compare, examples: '1', '1.1', '1.1.1', '2.0', etc.
     */
    public function isInstalledCodeAnUpgrade() {
        return $this->isSavedVersionLessThan( $this->getVersion() );
    }

    /**
     * Used to see if the installed code is an earlier version than the input version
     * @param string $aVersion version string.
     * @return bool true if the saved version is earlier (by natural order) than the input version
     */
    public function isSavedVersionLessThan( $aVersion ) {
        return $this->isVersionLessThan( $this->getVersionSaved(), $aVersion );
    }

    /**
     * Used to see if the installed code is the same or earlier than the input version.
     * Useful when checking for an upgrade. If you haven't specified the number of the newer version yet,
     * but the last version (installed) was 2.3 (for example) you could check if
     * For example, $this->isSavedVersionLessThanEqual('2.3') == true indicates that the saved version is not upgraded
     * past 2.3 yet and therefore you would perform some appropriate upgrade action.
     * @param string $aVersion version string.
     * @return bool true if the saved version is earlier (by natural order) than the input version
     */
    public function isSavedVersionLessThanEqual( $aVersion ) {
        return $this->isVersionLessThanEqual( $this->getVersionSaved(), $aVersion );
    }

    /**
     * @param string $version1 version string such as '1', '1.1', '1.1.1', '2.0', etc.
     * @param  string $version2 version string such as '1', '1.1', '1.1.1', '2.0', etc.
     * @return bool true if version_compare of $versions1 and $version2 shows $version1 as the same or earlier
     */
    public function isVersionLessThanEqual( $version1, $version2 ) {
        return ( version_compare( $version1, $version2 ) <= 0 );
    }

    /**
     * @param string $version1 version string such as '1', '1.1', '1.1.1', '2.0', etc.
     * @param string $version2 version string such as '1', '1.1', '1.1.1', '2.0', etc.
     * @return bool true if version_compare of $versions1 and $version2 shows $version1 as earlier
     */
    public function isVersionLessThan( $version1, $version2 ) {
        return ( version_compare( $version1, $version2 ) < 0 );
    }

    /**
     * Record the installed version to options.
     * This helps track was version is installed so when an upgrade is installed, it should call this when finished
     * upgrading to record the new current version
     * @return void
     */
    protected function saveInstalledVersion() {
        $this->setVersionSaved( $this->getVersion() );
    }
}