Each Loan Party will, and will cause each Subsidiary to, pay all Material Obligations, now existing or hereafter arising, as and when due and payable in accordance with customary trade practices, and pay and discharge or cause to be paid and discharged promptly all taxes, assessments and government charges or levies imposed upon it or upon its income and profits, or upon any of its property, real, personal or mixed, or upon any part thereof, before the same shall become in default, as well as all lawful claims for labor, materials and supplies or otherwise which, if unpaid, might become a lien or charge upon such properties or any part thereof; provided , however , that neither the Borrower nor any of its Subsidiaries shall be required to pay and discharge or cause to be paid and discharged any such tax, assessment, charge, levy or claim so long as the validity thereof shall be contested in good faith by appropriate proceedings, and the Borrower or such Subsidiary, as the case may be, shall have set aside on its books adequate reserves determined in accordance with GAAP with respect to any such tax, assessment, charge, levy or claim so contested; further , provided that, subject to the foregoing proviso, the Borrower and each of its Subsidiaries shall pay or cause to be paid all such taxes, assessments, charges, levies or claims upon the commencement of proceedings to foreclose any lien which has attached as security therefor.