code: def get_all(self):
          
          with mutex:
              items = self.values.items()
  
          result = []
          for k, v in items:
              # Check if is a single value dict (custom empty key)
              if not k or k == MetricDict.EMPTY_KEY:
                  key = None
              else:
                  key = decoder.decode(k)
              result.append((key, self.get(k)))
  
          return result
docs: Returns a list populated by tuples of 2 elements, first one is
              a dict with all the labels and the second elemnt is the value
              of the metric itself