system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
"""
agreements and understandings, negotiations, writings and commitments, either oral or written, in respect to the subject matter hereof are superseded by the terms of this Agreement. The Schedules and Exhibits to this Agreement are incorporated herein by reference and shall be deemed a part of this Agreement. This Agreement may be amended, or any term hereof modified, only by a written instrument duly executed by authorized representatives of each of the Parties. 15.3 Force Majeure. No Party shall be liable for any failure to perform, or be considered in breach of, its obligations under this Agreement (other than obligations to make payments of money) to the extent such performance has been delayed, interfered with or prevented by an event of Force Majeure, and the obligations of such Party under this Agreement (other than obligations to make payments of money) whose performance is affected by Force Majeure shall be suspended during, but not longer than, the continuance of the event of Force Majeure. Any Party that experiences an event of Force Majeure shall provide prompt notice of such event to the other Party, including and an estimate of the likely period of time during which its performance will be affected, and shall use reasonable efforts to remove the condition constituting Force Majeure. In the event of a prolonged condition of Force Majeure that makes it unreasonable to continue to perform other activities then being performed by the Parties and their Affiliates pursuant to this Agreement, the Parties shall consult directly as to whether they should appropriately scale back their respective activities in order to avoid waste or inappropriate usage of resources under the circumstances. 15.4 Notices. Any notice required or permitted to be given under this Agreement shall be in writing, shall specifically refer to this Agreement and shall be deemed to have been sufficiently given for all purposes if; mailed by first class certified or registered mail, postage prepaid (which notice shall be effective [***] ([***]) Business Days [***]); express delivery service (which notice shall be effective on the first Business Day after delivery to such service); or personally delivered to the appropriate addresses (which notice shall be effective upon delivery to such addresses) set forth below or to such other addresses or numbers for a Party as such Party may inform the other Party by giving [***] ([***]) Business Days' prior written notice: If to Xencor: Xencor, Inc. 111 West Lemon Avenue Monrovia, CA 91016 Attention: General Counsel 44 Source: AIMMUNE THERAPEUTICS, INC., 8-K, 2/5/2020 With copies to (which shall not constitute notice): Xencor, Inc. 111 West Lemon Avenue Monrovia, CA 91016 Attention: Chief Executive Officer Morgan, Lewis & Bockius LLP 1 Market Street, Spear Street Tower San Francisco, CA 94105 Attention: Benjamin Pensak If to Aimmune: Aimmune Therapeutics, Inc. 8000 Marina Boulevard Suite 300 Brisbane, CA 94005 Attention: General Counsel With copies to (which shall not constitute notice): Latham & Watkins LLP 140 Scott Drive Menlo Park, CA 94025 Attention: Patrick Pohlen Judith Hasko 15.5 Maintenance of Records. Aimmune shall keep and maintain all records required by Applicable Law or regulation (including records for intellectual property protection purposes) with respect to the Antibody and Product and shall, upon Xencor's written request, allow Xencor reasonable access to make copies of such records, at Xencor's expense. Aimmune must maintain such records for the greater of [***] ([***]) years or the time period required by Applicable Law. 15.6 Assignment. Neither Party may assign or transfer this Agreement or any rights or obligations hereunder without the prior written consent of the other Party, except that a Party may make such an assignment or transfer without the other Party's written consent to (a) any of its Affiliates, in whole or in part, or (b) any Third Party in connection with (i) the acquisition of such Party by or merger or consolidation of such Party with another entity or (ii) a merger, consolidation, sale of stock, sale of all or substantially all of such Party's assets or other similar transaction in which such Third Party either becomes the owner of all or substantially all of the business and assets of (y) such Party or (z) that portion of such Party's business or business unit relating to this Agreement. Any permitted successor or assignee of rights or obligations hereunder shall, in a writing delivered to the other Party, expressly assume the performance of such rights or obligations. Except as set forth in the immediately preceding sentence, in the event of an assignment or transfer as
"""

Extract the exact clause related to "Anti-Assignment" from the excerpt above.

assistant: Neither Party may assign or transfer this Agreement or any rights or obligations hereunder without the prior written consent of the other Party, except that a Party may make such an assignment or transfer without the other Party's written consent to (a) any of its Affiliates, in whole or in part, or (b) any Third Party in connection with (i) the acquisition of such Party by or merger or consolidation of such Party with another entity or (ii) a merger, consolidation, sale of stock, sale of all or substantially all of such Party's assets or other similar transaction in which such Third Party either becomes the owner of all or substantially all of the business and assets of (y) such Party or (z) that portion of such Party's business or business unit relating to this Agreement.