### Question:
Configuration { @Override public String toString() { StringBuilder builder = new StringBuilder(); builder.append("***** Configuration Details *****\n"); builder.append("Data Source=" + dataSource + "\n"); builder.append("Destination Bucket=" + destinationBucket + "\n"); builder.append("Source Bucket=" + sourceBucket + "\n"); builder.append("SQL Bucket=" + sqlBucket + "\n"); builder.append("File System=" + fileSystem + "\n"); builder.append("Mappings=" + mappings.toString() + "\n"); builder.append("*****************************"); return builder.toString(); }  String getDataSource(); String getDestinationBucket(); String getSourceBucket(); String getSqlBucket(); String getFileSystem(); List<Mapping> getMappings(); @Override String toString();  }### Answer:
@Test public void testToString() { System.out.println(configuration.toString()); String expected = "***** Configuration Details *****\n" + "Data Source=mimic\n" + "Destination Bucket=bucket1-stage\n" + "Source Bucket=bucket1-raw\n" + "SQL Bucket=sql-bucket\n" + "File System=file\n" + "Mappings=[\n" + "***** Mapping Details *****\n" + "Source Files=[file1.csv]\n" + "SQL File=sql/sql1.sql\n" + "Overflow Columns=[]\n" + "*****************************, \n" + "***** Mapping Details *****\n" + "Source Files=[file1.csv, file2.csv]\n" + "SQL File=sql2.sql\n" + "Overflow Columns=[]\n" + "*****************************, \n" + "***** Mapping Details *****\n" + "Source Files=[file1.csv]\n" + "SQL File=sql2.sql\n" + "Overflow Columns=[overflow1, overflow2]\n" + "*****************************]\n" + "*****************************"; assertEquals(expected, configuration.toString()); }