@staticmethod
def getId(obj, idFormat='_V%i_'):
    """returns an id string for the given object which has the following
           two properties:
            - It is unique for this object during all its life
            - It is a string that can be used as a variable or method name

        :param obj: (object) the python object whose id is requested
        :param idFormat: (str) a format string containing a "`%i`" which,
                         when expanded must be a valid variable name
                         (i.e. it must match
                         `[a-zA-Z_][a-zA-Z0-9_]*`). The default is `_V%i_`
        """
    return idFormat % id(obj)
