CYRUSONE LP and CYRUSONE FINANCE CORP. as Issuers, CYRUSONE INC. as Guarantor, and WELLS FARGO BANK, N.A. as Trustee 2.150% SENIOR NOTES DUE 2030 FOURTH SUPPLEMENTAL INDENTURE Dated as of September 21, 2020 TO THE INDENTURE Dated as of December 5, 2019