'Adds a link to source\'s token representations using default settings.
Constructs a LinkedFeatureChannel proto and adds it to the spec, using
defaults to assign the name, component, translator, and layer of the
channel.  The user must provide fml and embedding_dim.
Args:
source: SyntaxComponentBuilder object to pull representations from.
source_layer: Optional override for a source layer instead of the default.
**kwargs: Forwarded arguments to the LinkedFeatureChannel proto.'

def add_token_link(self, source=None, source_layer=None, **kwargs):

    if (source_layer is None):
        source_layer = source.default_source_layer()
    self.spec.linked_feature.add(name=source.spec.name, source_component=source.spec.name, source_layer=source_layer, source_translator=source.default_token_translator(), **kwargs)
