At the trial or upon any hearing, a part or all of a deposition, so far as otherwise admissible under the rules of evidence, may be used if the witness is unavailable. Any deposition may also be used by any party for the purpose of contradicting or impeaching the testimony of the deponent as a witness. If only a part of a deposition is offered in evidence by a party, an adverse party may require the offering of all of it which is relevant to the part offered and any party may offer other parts. A witness is not unavailable if the exemption, refusal to testify, claim of lack of memory, inability, or absence of such witness is due to the procurement or wrongdoing of the party offering the deposition at the hearing or trial for the purpose of preventing the witness from attending or testifying.