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:
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parties. 44 Source: ATN INTERNATIONAL, INC., 10-Q, 11/8/2019 hereunder, including the Build Services contemplated in the Build Addendum, shall commence upon Location Acceptance of the applicable Cell Site and continue for a period equal to [***] from Location Acceptance of the applicable Cell Site (the "Workmanship Warranty Period"). For the duration of such warranty period, Vendor represents and warrants to AT&T as follows: (i) Material (excluding AT&T Provided Equipment) furnished hereunder will be merchantable, free from defects in design, material and workmanship, fit and sufficient for the purposes set forth in the Agreement, free from all Liens at the time of Location Acceptance, and will during the Material Warranty Period strictly conform to and perform in accordance with applicable Specifications, drawings and samples. (ii) Services provided hereunder will be performed (A) in a professional and efficient manner, in strict compliance with the Specifications, (B) with the care, skill, and diligence, and in accordance with professional industry standards and practices, currently recognized in Vendor's profession or industry, (C) in compliance with all applicable Laws and all descriptions and representations as to the Services (including performance capabilities, accuracy, completeness, characteristics, specifications, configurations, standards, functions and requirements) set forth in this Agreement, the Build Addendum and the Maintenance Addendum (and all schedules thereto), and (D) by personnel with appropriate experience, knowledge and competence. If Vendor fails to meet applicable professional standards, Vendor will, without additional compensation, promptly correct or revise any errors or deficiencies in the Services furnished hereunder. (b) In addition, Vendor represents and warrants that: (i) Vendor is duly organized, validly existing and in good standing under the laws of its state of formation with all requisite power to enter into and perform its obligations under this Agreement, the Build Addendum and the Maintenance Addendum and has the full power, authority and right to provide the Material and Services specified herein; (ii) The execution, delivery and performance of this Agreement, the Build Addendum and the Maintenance Addendum has been duly and validly authorized and approved by all necessary action of Vendor and will constitute legal, valid and binding obligations of Vendor enforceable in accordance with their respective terms; (iii) Vendor has (or will have at the time of the performance of the applicable Services) and will continue to hold during the performance of the applicable Services during the Term of this Agreement (or the Build Addendum Term or Maintenance Addendum Term, as applicable) all permits, licenses and Contracts required to enter into and perform this Agreement, the Build Addendum and Maintenance Addendum and to deliver the Material and Services hereunder; (iv) As of the Effective Date, there are no actions, suits, or proceedings, pending or threatened, which will have a material adverse effect on Vendor's ability to fulfill its Proprietary and Confidential This Agreement and information contained therein is not for use or disclosure outside of AT&T, its Affiliates, and third party representatives, and Vendor except under written agreement by the contracting parties. 45 Source: ATN INTERNATIONAL, INC., 10-Q, 11/8/2019 obligations under this Agreement and Vendor will immediately notify AT&T if, during the Term, Vendor becomes aware of any such action, suit, or proceeding; (v) Vendor has, as of the Effective Date, and will continue to have during the Term of the Build Addendum or Maintenance Addendum, as applicable, all necessary skills, rights, and financial resources (including any required binding commitments for financing from third Persons) applicable to such obligations then in effect, and authority to enter into this Agreement, the Build Addendum or the Maintenance Addendum, including the authority to provide or license the Material or Services, and satisfy all of its obligations hereunder and thereunder; (vi) As of the Effective Date, no third party claim has been alleged against Vendor that any Material and Services provided hereunder infringes upon such third party's intellectual property rights and Vendor will immediately notify AT&T if, during the Term, Vendor becomes aware of any such third party claim; (vii) No consent, approval, or withholding of objection is required from any entity, including any governmental authority, with respect to the entering into or the performance of this Agreement, the Build Addendum or the Maintenance Addendum; (viii) At the time of Location Acceptance (or, if later, at the time of Delivery), the Material and Services will be provided free of any Lien of any kind; (ix) Vendor will be fully responsible and liable for all acts, omissions, and Work performed by any of its representatives, including any Subcontractors; (x) All representatives, including Subcontractors, will strictly
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Extract the exact clause related to "Warranty Duration" from the excerpt above.

assistant: hereunder, including the Build Services contemplated in the Build Addendum, shall commence upon Location Acceptance of the applicable Cell Site and continue for a period equal to [***] from Location Acceptance of the applicable Cell Site (the "Workmanship Warranty Period").