      default_empty_html = []
  
      def get_value(self, dictionary):
          # We override the default field access in order to support
          # lists in HTML forms.
          if html.is_html_input(dictionary):
              ret = dictionary.getlist(self.field_name)
 
</s> remove         'not_a_list': _('Expected a list of items but got type "{input_type}".')
 </s> add         'not_a_list': _('Expected a list of items but got type "{input_type}".'),
        'empty': _('This selection may not be empty.') </s> remove     'label', 'help_text', 'style', 'error_messages'
 </s> add     'label', 'help_text', 'style', 'error_messages', 'allow_empty' </s> remove     'label', 'help_text', 'style', 'error_messages',
 </s> add     'label', 'help_text', 'style', 'error_messages', 'allow_empty',
    def __init__(self, *args, **kwargs):
        self.allow_empty = kwargs.pop('allow_empty', True)
        super(MultipleChoiceField, self).__init__(*args, **kwargs)

      default_empty_html = []
  
    def __init__(self, *args, **kwargs):
        self.allow_empty = kwargs.pop('allow_empty', True)
        super(MultipleChoiceField, self).__init__(*args, **kwargs)

      def get_value(self, dictionary):
          # We override the default field access in order to support
          # lists in HTML forms.
          if html.is_html_input(dictionary):
              ret = dictionary.getlist(self.field_name)
keep add keep keep keep keep keep
 Added allow_empty flag for ListField, ListSerializer, ManyRelation, MultipleChoiceField. 
rest_framework/fields.py