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:
"""
Exhibit 10.4 Execution Version GAS TRANSPORTATION AGREEMENT This Gas Transportation Agreement (this "Agreement") is hereby made and entered into on the 14t h day of April, 2015 (the "Effective Date") by and between PennTex North Louisiana Operating, LLC, a Delaware limited liability company ("Transporter"), and MRD Operating LLC, a Delaware limited liability company ("Customer"). Hereinafter, Transporter and Customer may sometimes be referred to collectively as the "Parties" and individually as a "Party." WITNESSETH WHEREAS, Transporter owns and operates a natural gas transportation system and related facilities; and WHEREAS, Customer owns or controls, and has the right, to deliver Gas (as hereinafter defined) for transportation and desires to have Transporter provide such service under the terms and conditions of this Agreement. NOW, THEREFORE, in consideration of the premises and the mutual covenants herein contained, the Parties covenant and agree as follows: Article I. Definitions For the purposes of this Agreement, the following definitions have the meanings as set forth below: "Affiliate" shall mean, when used with respect to any Person, any other Person that, directly or indirectly, through one or more intermediaries, controls, is controlled by, or is under common control with such Person. For this purpose, "control" of any Person shall mean the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of such Person, by ownership of voting interest, by contract or otherwise. For the purposes of this Agreement, (i) with respect to PennTex Midstream Partners, LLC and its subsidiaries, the term "Affiliate" shall exclude Memorial Resource Development Corp. and each of its subsidiaries and (ii) with respect to Memorial Resource Development Corp. and its subsidiaries, the term "Affiliate" shall exclude PennTex Midstream Partners, LLC and each of its subsidiaries. "AMI/MEA Agreement" shall mean that certain Amended and Restated Area of Mutual Interest and Midstream Exclusivity Agreement dated April 14, 2015 among PennTex North Louisiana, LLC, Customer, PennTex NLA Holdings, LLC and MRD WHR LA Midstream LLC, as such agreement may be amended, supplemented or otherwise modified from time to time. "Btu" shall mean one British thermal unit, the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit at standard reference conditions. "Business Day" shall mean any day (other than a Saturday or Sunday) on which commercial banking institutions in Houston, Texas are generally open for business. Source: PENNTEX MIDSTREAM PARTNERS, LP, S-1/A, 4/16/2015 "Cash-out Price" shall have the meaning set forth for such term in Article IV. "Central Clock Time" shall mean the current time in the Central Time Zone taking into consideration the seasonal changes back and forth between Daylight Savings and Standard time. "Commencement Date" shall be the first day of the Month following the date Transporter notifies Customer that (i) the Transportation System is operational to the extent necessary to commence commercial service with respect to the receipt of Customer Gas at the Point of Receipt at the tailgate of the Lincoln Parish Plant and delivery of such Gas to the Points of Delivery located downstream of the Lincoln Parish Plant, (ii) the Lincoln Parish Plant is operational to the extent necessary to commence commercial service with respect to the receipt and processing of Customer Gas, and (iii) the Points of Delivery listed on Exhibit A that are owned by Transporter or its Affiliate are operational and all necessary interconnect agreements with Interconnecting Pipelines necessary to deliver Gas to such Points of Delivery are in effect to the extent necessary to commence commercial service with respect to the delivery (but, for the avoidance of doubt, not the further downstream transportation) of Customer's Gas. Transporter will not be responsible for delays to the Commencement Date due to the action or inaction of Customer or Third Party Operators. "Commencement Date Facilities" shall have the meaning given to such term in Article II. "Contract Year" shall mean a period commencing at 9:00 a.m., Central Clock Time, on the Commencement Date and ending at 9:00 a.m., Central Clock Time on the same day and calendar month of the following calendar year and thereafter for succeeding periods of twelve (12) consecutive Months each. "Customer" shall have the meaning given to such term in the preamble of this Agreement. "Customer's Firm Service Gas" shall mean, an amount of Customer Gas equal to 400,000 MMBtu per Day; provided, however, (y) Customer's Firm Service Gas shall be increased by the additional amount of Transportation System capacity provided pursuant to a New Facility, and (z) if any Plant
"""

Extract the exact clause related to "Agreement Date" from the excerpt above.

assistant: 14t h day of April, 2015