PER CURIAM.
The respondent, Arthur F. Lederle, Chief Judge of the United States District Court for the Eastern District of Michigan, having filed a response to the order to show cause heretofore issued;
And it appearing that subsequent thereto said Court held a hearing in the causes herein referred to, and on March 21, 1952 rendered a decision in the same, and by reason thereof the action sought by the petitioners herein has taken place and the proceeding has become moot; It Is Ordered that petitioners’ application for a mandamus be denied.