@Nullable
  TerminalBlock withoutLastOperation() {
    if(myOperations.length == 1) return null;
    Operation[] operations = new Operation[myOperations.length - 1];
    System.arraycopy(myOperations, 0, operations, 0, operations.length);
    return new TerminalBlock(operations, operations[operations.length - 1].getVariable(), myStatements);
  }
@Nullable
  TerminalBlock withoutLastOperation()