Upon the trial of any case any party thereto or any person for whose immediate benefit the action is prosecuted or defended, or the officers, directors, managing agents or foreman of any party to the action, may be called and examined as if under cross-examination at the instance of any adverse party. The party calling for the examination is not concluded thereby but may rebut the testimony thus given by countertestimony and may impeach the witness by proof of prior inconsistent statements.