Normalizes coordinate tuple.

    * **value** must be a ``tuple`` or ``list``.
    * **value** must have exactly two items.
    * **value** items must be an :ref:`type-int-float`.
    * Returned value is a ``tuple`` of two values of the same type as
      the input values.

def normalizeCoordinateTuple(value):
    """
    Normalizes coordinate tuple.

    * **value** must be a ``tuple`` or ``list``.
    * **value** must have exactly two items.
    * **value** items must be an :ref:`type-int-float`.
    * Returned value is a ``tuple`` of two values of the same type as
      the input values.
    """
    if not isinstance(value, (tuple, list)):
        raise TypeError("Coordinates must be tuple instances, not %s."
                        % type(value).__name__)
    if len(value) != 2:
        raise ValueError("Coordinates must be tuples containing two items, "
                         "not %d." % len(value))
    x, y = value
    x = normalizeX(x)
    y = normalizeY(y)
    return (x, y)