# add method

bool add (String value)

Add the class `value` to element.

add and addAll are the Dart equivalent of jQuery's addClass.

If this CssClassSet corresponds to one element. Returns true if `value` was added to the set, otherwise false.

If this corresponds to many elements, `null` is always returned.

`value` must be a valid 'token' representing a single class, i.e. a non-empty string containing no whitespace. To add multiple classes use addAll.

## Implementation

    bool add(String value);