# add method

StreamBuilder<T> add(

1. T element

)

Adds an element to the stream being built.

Throws NoGuaranteeException if the builder has already been built.

## Example

    builder.add('Hello');
    builder.add('World');

## Implementation

    StreamBuilder<T> add(T element) {
      if (_built) {
        throw NoGuaranteeException('StreamBuilder has already been built');
      }
      _elements.add(element);
      return this;
    }