fix problem test (SXXSF)

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1923820 13f79535-47bb-0310-9956-ffa450edef68

poi-ooxml/src/main/java/org/apache/poi/xssf/streaming/SXSSFCell.java

@@ -17,8 +17,6 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 
 package org.apache.poi.xssf.streaming;
 
-import java.text.DateFormat;
-import java.text.SimpleDateFormat;
 import java.time.LocalDateTime;
 import java.util.Calendar;
 import java.util.Date;
@@ -27,7 +25,17 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import org.apache.poi.ss.SpreadsheetVersion;
 import org.apache.poi.ss.formula.FormulaParseException;
 import org.apache.poi.ss.formula.eval.ErrorEval;
-import org.apache.poi.ss.usermodel.*;
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellBase;
+import org.apache.poi.ss.usermodel.CellStyle;
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.Comment;
+import org.apache.poi.ss.usermodel.DataFormatter;
+import org.apache.poi.ss.usermodel.DateUtil;
+import org.apache.poi.ss.usermodel.FormulaError;
+import org.apache.poi.ss.usermodel.Hyperlink;
+import org.apache.poi.ss.usermodel.RichTextString;
+import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.ss.util.CellRangeAddress;
 import org.apache.poi.ss.util.CellReference;
 import org.apache.poi.util.*;