code: def parse(self, value):
          
          indices = []
          if not isinstance(value, dict):
              # We interpret non-list inputs as a list of one element, for
              # compatibility with certain EC2 APIs.
              return [self.item.coerce(value)]
          for index in value.keys():
              try:
                  indices.append(int(index))
              except ValueError:
                  raise UnknownParameterError(index)
          result = [None] * len(value)
          for index_index, index in enumerate(sorted(indices)):
              v = value[str(index)]
              if index < 0:
                  raise UnknownParameterError(index)
              result[index_index] = self.item.coerce(v)
          return result
docs: Convert a dictionary of {relative index: value} to a list of parsed
          C{value}s.