code: function escapeString(str) {
  
      if(str === undefined) {
          throw new Error('\'str\' is required');
      }
  
      if(str === null) {
          throw new Error('\'str\' must not be null');
      }
  
      if(typeof str !== 'string') {
          throw new Error('\'str\' must be a string');
      }
  
      /*
       * Need to escape backslashes (\) first because escaping ' and " will also 
       * add a \, which interferes with \ escaping.
       */
      var escaped_str = str;
      // regex replace all \ to \\
      escaped_str = escaped_str.replace(/\\/g, '\\\\');
      // regex replace all ' to \'
      escaped_str = escaped_str.replace(/'/g, '\\\'');
      // regex replace all " to \"
      escaped_str = escaped_str.replace(/"/g, '\\"');
  
      return escaped_str;
  
  }
docs: Escapes single, double quotes, and backslashes of the given string.
  @name escapeString
  @param {string} str - string to escape
  @returns {string} the escaped string