public static BytecodeBipush at(Method method, int bci) {
   BytecodeBipush b = new BytecodeBipush(method, bci);
   if (Assert.ASSERTS_ENABLED) {
     b.verify();
   }
   return b;
 }
 /** Like at, but returns null if the BCI is not at bipush */
 public static BytecodeBipush atCheck(Method method, int bci) {
   BytecodeBipush b = new BytecodeBipush(method, bci);
   return (b.isValid() ? b : null);
 }