docs: function(value, params, property) {
              value = +value;
  
              if ('min' in params && value < params.min) {
                  throw new Error('Value "' + value +
                      '" of property "' + property + '" must not be less then "' + params.min + '"!');
              }
              if ('max' in params && value > params.max) {
                  throw new Error('Value "' + value +
                      '" of property "' + property + '" must not be greater then "' + params.max + '"!');
              }
              return value;
          }