  
  class MultipleChoiceField(ChoiceField):
      default_error_messages = {
          'invalid_choice': _('"{input}" is not a valid choice.'),
          'not_a_list': _('Expected a list of items but got type "{input_type}".')
      }
      default_empty_html = []
  
      def get_value(self, dictionary):
          # We override the default field access in order to support
 
</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 list may not be empty.') </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 list may not be empty.') </s> remove         (['1', '2', '3'], [1, 2, 3])
 </s> add         (['1', '2', '3'], [1, 2, 3]),
        ([], [])
        'not_a_list': _('Expected a list of items but got type "{input_type}".'),
        'empty': _('This selection may not be empty.')
  
  class MultipleChoiceField(ChoiceField):
      default_error_messages = {
          'invalid_choice': _('"{input}" is not a valid choice.'),
        'not_a_list': _('Expected a list of items but got type "{input_type}".'),
        'empty': _('This selection may not be empty.')
      }
      default_empty_html = []
  
      def get_value(self, dictionary):
          # We override the default field access in order to support
keep keep keep keep replace keep keep keep keep keep
 Added allow_empty flag for ListField, ListSerializer, ManyRelation, MultipleChoiceField. 
rest_framework/fields.py