How to use the ptype.TupleT function in ptype

def combine(self, other):
    if isinstance(other, TupleT) and len(other.elt_types) == len(self.elt_types):
      combined_elt_types = [t1.combine(t2) for \
                            (t1, t2) in zip(self.elt_types, other.elt_tyepes)]
      if combined_elt_types != self.elt_types:
        return TupleT(combined_elt_types)
      else:
        return self
    else:
      raise IncompatibleTypes(self, other)

def type_of_value(x):
  if np.isscalar(x):
    return type_of_scalar(x)
  elif isinstance(x, tuple):
    elt_types = map(type_of_value, x)
    return TupleT(elt_types)
  elif isinstance(x, np.ndarray):
    return ArrayT(from_dtype(x.dtype), np.rank(x))
  else:
    raise RuntimeError("Unsupported type " + str(type(x)))

def combine(self, other):
    if isinstance(other, TupleT) and len(other.elt_types) == len(self.elt_types):
      combined_elt_types = [t1.combine(t2) for \
                            (t1, t2) in zip(self.elt_types, other.elt_tyepes)]
      if combined_elt_types != self.elt_types:
        return TupleT(combined_elt_types)
      else:
        return self
    else:
      raise IncompatibleTypes(self, other)

def repeat_tuple(t, n):
  """Given the base type t, construct the n-tuple t*t*...*t"""
  elt_types = tuple([t] * n)
  if elt_types in _tuple_types:
    return _tuple_types[elt_types]
  else:
    tuple_t = TupleT(elt_types)
    _tuple_types[elt_types] = tuple_t
    return tuple_t

def make_tuple_type(elt_types):
  """
  Use this memoized construct to avoid
  constructing too many distinct tuple type
  objects and speeding up equality checks
  """ 
  key = tuple(elt_types)
  if key in _tuple_types:
    return _tuple_types[key]
  else:
    t = TupleT(key)
    _tuple_types[key] = t
    return t