@Nullable
  private GrExpression getRValue(GrAssignmentExpression expression) {
    GrExpression rValue = expression.getRValue();
    if (rValue == null) return null;

    GrExpression lValue = expression.getLValue();
    IElementType opToken = expression.getOperationTokenType();
    if (opToken == GroovyTokenTypes.mASSIGN) return rValue;
    Pair<String, IElementType> pair = GenerationUtil.getBinaryOperatorType(opToken);
    LOG.assertTrue(pair != null);

    return factory.createExpressionFromText(lValue.getText() + pair.getFirst() + rValue.getText(), expression);
  }
@Nullable
  private GrExpression getRValue(GrAssignmentExpression expression)