KNOW ALL PERSONS BY THESE PRESENTS that BROAD STREET
PRINCIPAL INVESTMENTS, L.L.C. (the "Company") does
hereby make, constitute and appoint each of Jamison
Yardley and Jennifer Lee, acting individually, its
true and lawful attorney, to execute and deliver in
its name and on its behalf whether the Company is
acting individually or as representative of others,
any and all filings required to be made by the Company
under the Securities Exchange Act of 1934, (as amended,
the "Act"), with respect to securities which may be
deemed to be beneficially owned by the Company under
the Act, giving and granting unto each said attorney-in-fact
power and authority to act in the premises as fully and to
all intents and purposes as the Company might or could do if
personally present by one of its authorized signatories, hereby
ratifying and confirming all that said attorney-in-fact shall
lawfully do or cause to be done by virtue hereof.
THIS POWER OF ATTORNEY shall remain in full force and
effect until the earlier of (i) May 17, 2022 and (ii) such
time that it is revoked in writing by the undersigned;
provided that in the event the attorney-in-fact ceases to
be an employee of the Company or its affiliates or ceases
to perform the function in connection with which he/she was
appointed attorney-in-fact prior to such time, this Power of
Attorney shall cease to have effect in relation to such
attorney-in-fact upon such cessation but shall continue
in full force and effect in relation to any remaining
attorneys-in-fact. The Company has the unrestricted
right unilaterally to revoke this Power of Attorney.
This Power of Attorney shall be governed by, and construed
in accordance with, the laws of the State of New York,
without regard to rules of conflicts of law.
IN WITNESS WHEREOF, the undersigned has duly subscribed these
presents as of May 17, 2019.
BROAD STREET PRINCIPAL INVESTMENTS, L.L.C.
By: /s/ William Y. Eng
Name: William Y. Eng
Title: Vice President