GREATER PENNSYLVANIA CARPENTERS PENSION FUND, derivatively on behalf of nominal defendant Imperva, Inc., Plaintiff-Below, Appellant, v. Charles GIANCARLO, Theresia Gouw, Shlomo Kramer, Steven Krausz, Albert Pimentel, Frank Slootman, David Strohm, James Tolonen, and Imperva, Inc., Defendants-Below, Appellees