static sanitize(value) {
        if (value instanceof RegExp) {
            return value.source;
        }

        if (typeof value === 'number') {
            return value;
        }

        if (typeof value !== 'string') {
            return '';
        }

        // Regular expression to match meta characters
        // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/regexp
        const toEscape = /([\].|*?+(){}^$\\:=[])/g;

        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/lastMatch
        const lastMatch = '$&';

        // Escape meta characters
        return value.replace(toEscape, `\\${lastMatch}`);
    }
Escape meta-characters in the parameter and make it safe for adding to the expression
@static
@param {(string|RegExp|number)} value object to sanitize
@returns {string} sanitized value
@memberof VerbalExpression