code: def _identify_dict(core):
      
      if not core:
          return {}, 1, (), int
  
      core = core.copy()
      key = sorted(core.keys(), key=chaospy.poly.base.sort_key)[0]
      shape = numpy.array(core[key]).shape
      dtype = numpy.array(core[key]).dtype
      dim = len(key)
      return core, dim, shape, dtype
docs: Specification for a dictionary.