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:
"""
shall designate by written notice to the other: ENERGY XXI USA, INC. Attn: Phone: Fax: Email address: ENERGY XXI GULF COAST, INC. Attn: Phone: Fax: Email address: 14 ARTICLE 15 ASSIGNMENT 15.1 Assignment. (a) Shipper shall have the right to assign, or transfer all, but not less than all, of its rights and obligations under this Agreement with the prior written consent of Transporter, which consent may be withheld in Transporter's sole discretion. (b) No assignment or transfer of this Agreement shall be effective as to Transporter unless and until Transporter has been provided written notice thereof. 15.2 Encumbrance. (a) Shipper shall not pledge, encumber or grant any security interest with respect to any portion of its interests or rights under this Agreement. (b) Transporter shall have the right to pledge, encumber or otherwise grant security interests in its interests or rights under this Agreement. 15.3 Nothing herein shall prevent or prohibit Shipper, without consent of Transporter, from engaging and using contractors and subcontractors to perform services, for the benefit of Shipper, in connection with the performance by Shipper of its obligations under this Agreement. ARTICLE 16 MISCELLANEOUS 16.1 Applicable Laws. This Agreement is subject to, and the Parties shall comply with, all valid present and future laws, regulations, rules and orders of Governmental Authorities now or hereafter having jurisdiction over the Parties, this Agreement, or the Services performed or the facilities utilized under this Agreement. 16.2 Authorizations. The Parties hereto represent that they have all requisite corporate and/or company authorizations necessary or proper to consummate this Agreement. 16.3 Entirety. This Agreement constitutes the entirety of the understanding between the Parties with respect to the subject matter dealt with herein, and replaces and supersedes all prior agreements, conditions, understandings, representations and warranties made between the Parties with respect to the subject matter hereof, whether written or oral. It is further agreed that no amendment, modification or change herein shall be enforceable, except as specifically provided for in this Agreement, unless reduced to writing and executed by both Parties. 16.4 Governing Law; Jurisdiction; Jury Waiver. (a) The validity, construction and performance of this Agreement shall be governed by the laws of the State of Texas, not including any of its conflicts of law rules that would direct or refer to the laws of another jurisdiction. The Parties have allocated liability risk pursuant to this Agreement and therefore intend that no anti-indemnity law, rule or regulation apply hereto. 15 (b) The Parties agree that the appropriate, exclusive and convenient forum for any disputes between the Parties arising out of this Agreement or the transactions contemplated hereby shall be in any state or federal court in Harris County, Texas, and each of the Parties irrevocably submits to the jurisdiction of such courts solely in respect of any proceeding arising out of or related to this Agreement. The Parties further agree that the Parties shall not bring suit with respect to any disputes arising out of this Agreement or the transactions contemplated hereby in any court or jurisdiction other than the above specified courts. (c) EACH PARTY HERETO WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY RIGHT IT MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY DISPUTE ARISING FROM OR UNDER THIS AGREEMENT. 16.5 Non-Waiver. No waiver by either Party hereto of any one or more defaults by the other in the performance of any of the provisions of this Agreement shall be construed as a waiver of any other default or defaults whether of a like kind or different nature. Any delay, less than any applicable statutory period of limitations, in asserting or enforcing any rights under this Agreement, shall not be deemed a waiver of such rights. Failure of either Party to enforce any provision of this Agreement or to require performance by the other Party of any of the provisions hereof shall not be construed to affect the validity of this Agreement or any part thereof, or the right of either Party thereafter to enforce each and every provision hereof. 16.6 Severability. If any term or other provision or portion of a provision of this Agreement is determined to be invalid, illegal or incapable of being enforced by any rule of Law or public policy, all other terms and conditions of this Agreement shall nevertheless remain in full force and effect. 16.7 Amendments. This Agreement shall not be altered or amended, except by an agreement in writing executed by all parties to this Agreement in accordance
"""

Extract the exact clause related to "Covenant Not To Sue" from the excerpt above.

assistant: Not found.