1*a24ffb47SSadaf Ebrahimiimport org.checkerframework.checker.nullness.qual.EnsuresNonNullIf; 2*a24ffb47SSadaf Ebrahimiimport org.checkerframework.checker.nullness.qual.NonNull; 3*a24ffb47SSadaf Ebrahimiimport org.checkerframework.checker.nullness.qual.Nullable; 4*a24ffb47SSadaf Ebrahimi 5*a24ffb47SSadaf Ebrahimipackage com.google.common.base; 6*a24ffb47SSadaf Ebrahimi 7*a24ffb47SSadaf Ebrahimiclass Strings { 8*a24ffb47SSadaf Ebrahimi @EnsuresNonNullIf(result = false, expression = "#1") 9*a24ffb47SSadaf Ebrahimi static boolean isNullOrEmpty(@Nullable String str); 10*a24ffb47SSadaf Ebrahimi} 11*a24ffb47SSadaf Ebrahimi 12*a24ffb47SSadaf Ebrahimiclass Preconditions { 13*a24ffb47SSadaf Ebrahimi static <T extends @NonNull Object> T checkNotNull(T reference, @Nullable Object errorMessage); 14*a24ffb47SSadaf Ebrahimi} 15