Sets default params.

def _setDefault(self, **kwargs):
        """
        Sets default params.
        """
        for param, value in kwargs.items():
            p = getattr(self, param)
            if value is not None and not isinstance(value, JavaObject):
                try:
                    value = p.typeConverter(value)
                except TypeError as e:
                    raise TypeError('Invalid default param value given for param "%s". %s'
                                    % (p.name, e))
            self._defaultParamMap[p] = value
        return self