static String suggestVarName(GrExpression expr, ExpressionContext expressionContext) {
    final DefaultGroovyVariableNameValidator nameValidator =
      new DefaultGroovyVariableNameValidator(expr, expressionContext.myUsedVarNames, true);
    final String[] varNames = GroovyNameSuggestionUtil.suggestVariableNames(expr, nameValidator);

    LOG.assertTrue(varNames.length > 0);
    expressionContext.myUsedVarNames.add(varNames[0]);
    return varNames[0];
  }
static String suggestVarName(GrExpression expr, ExpressionContext expressionContext)