Section 11-1.7. Limitations on powers and immunities of executors and

testamentary trustees
    (a) The attempted grant to an executor or testamentary trustee, or the
  successor of either, of  any  of  the  following  enumerated  powers  or
  immunities is contrary to public policy:
    (1)  The  exoneration  of such fiduciary from liability for failure to
  exercise reasonable care, diligence and prudence.
    (2) The power to make a binding and conclusive fixation of  the  value
  of any asset for purposes of distribution, allocation or otherwise.
    (b)  The  attempted  grant  in  any  will  of any power or immunity in
  contravention of the terms of this section shall be void but  shall  not
  be  deemed  to  render  such  will invalid as a whole, and the remaining
  terms of the will shall, so far as possible, remain effective.
    (c) Any person interested in  an  estate  or  testamentary  trust  may
  contest  the  validity  of  any purported grant of any power of immunity
  within the purview of this  section  without  diminishing  or  affecting
  adversely his interest in the estate or trust, any provision in any will
  to the contrary notwithstanding.