Tests whether this instance contains a param with a given
        (string) name.

def hasParam(self, paramName):
        """
        Tests whether this instance contains a param with a given
        (string) name.
        """
        if isinstance(paramName, basestring):
            p = getattr(self, paramName, None)
            return isinstance(p, Param)
        else:
            raise TypeError("hasParam(): paramName must be a string")