public static BooleanSupplier proposition(Supplier<Boolean> supplier) {
        dbc.precondition(supplier != null, "cannot adapt a null supplier");
        return supplier::get;
    }
public static BooleanSupplier proposition ( Supplier < Boolean > supplier ) { dbc . precondition ( supplier != null , "cannot adapt a null supplier" ) ; return supplier :: get ; }
Adapts a supplier to a proposition.

@param supplier the supplier to be adapted
@return the adapted proposition