      """
      Base class for related model fields.
      """
      widget = widgets.Select
      cache_choices = False
      empty_label = None
  
      def __init__(self, *args, **kwargs):
 
</s> remove     A field that represents the model's identity using a hyperlink.
 </s> add     Represents the instance, or a property on the instance, using hyperlinking.
    If not overridden, this represents a to-one relatinship, using the unicode
    representation of the target.
      """
      Base class for related model fields.
    If not overridden, this represents a to-one relatinship, using the unicode
    representation of the target.
      """
      widget = widgets.Select
      cache_choices = False
      empty_label = None
  
      def __init__(self, *args, **kwargs):
keep add keep keep keep keep keep keep
 Relational field support in browseable API.

Add slug relational fields.
Add quickstart. 
rest_framework/fields.py