          For generic class based views we return information about
          the fields that are accepted for 'PUT' and 'POST' methods.
          """
          actions = {}
          for method in set(['PUT', 'POST']) & set(view.allowed_methods):
              view.request = clone_request(request, method)
              try:
                  # Test global permissions
                  if hasattr(view, 'check_permissions'):
                      view.check_permissions(view.request)
 
</s> remove         ])
 </s> add         } </s> remove         field_names = set([
 </s> add         field_names = { </s> remove         missing = dict([
            (field_name, self.missing_message)
 </s> add         missing = {
            field_name: self.missing_message </s> remove         ])
 </s> add         } </s> remove         return dict([
            (key, value if isinstance(value, list) else [value])
 </s> add         return {
            key: value if isinstance(value, list) else [value]
        for method in {'PUT', 'POST'} & set(view.allowed_methods):
          For generic class based views we return information about
          the fields that are accepted for 'PUT' and 'POST' methods.
          """
          actions = {}
        for method in {'PUT', 'POST'} & set(view.allowed_methods):
              view.request = clone_request(request, method)
              try:
                  # Test global permissions
                  if hasattr(view, 'check_permissions'):
                      view.check_permissions(view.request)
keep keep keep keep replace keep keep keep keep keep
 Replaced all dict and set conversions from lists to dict and set literals. 
rest_framework/metadata.py