If more than one series of bonds shall be issued under sections 176.010 to 176.080 payable from the net income and revenues of any project or projects, priority of lien thereof on such net income and revenues shall depend on the provisions of the proceedings authorizing the issuance of such bonds, it being within the discretion of the governing body, at the time it authorizes any such series, to provide that subsequent series of bonds payable from such net income and revenues may not be issued, that subsequent series of bonds shall be subordinate as to lien, or that subsequent series of bonds shall enjoy parity of lien if such conditions and restrictions as may be specified in such proceedings can be met.