### Question:
BlurThriftHelper { public static RecordMutation findRecordMutation(RowMutation mutation, Record record) { for (RecordMutation recordMutation : mutation.recordMutations) { if (match(recordMutation, record)) { return recordMutation; } } return null; }  static Selector newSelector(String locationId); static BlurQuery newSimpleQuery(String queryStr); static RowMutation newRowMutation(String table, String rowId, RecordMutation... mutations); static RowMutation newRowMutation(RowMutationType type, String table, String rowId,
      RecordMutation... mutations); static Record newRecord(String family, String recordId, Column... columns); static Row newRow(String rowId, Record... records); static Column newColumn(String name, String value); static RecordMutation newRecordMutation(String family, String recordId, Column... columns); static RecordMutation newRecordMutation(RecordMutationType type, String family, String recordId,
      Column... columns); static RecordMutation findRecordMutation(RowMutation mutation, Record record); static boolean match(RecordMutation mutation, Record record); static boolean match(Record left, Record right); static RowMutation newRowMutation(String table, Row row);  }### Answer:
@Test public void testFindRecordMutation() { RecordMutation rm1 = BlurThriftHelper.newRecordMutation("test-family", "record-1", BlurThriftHelper.newColumn("a", "b")); RecordMutation rm2 = BlurThriftHelper.newRecordMutation("test-family", "record-2", BlurThriftHelper.newColumn("c", "d")); RecordMutation rm3 = BlurThriftHelper.newRecordMutation("test-family-2", "record-1", BlurThriftHelper.newColumn("e", "f")); RowMutation row = BlurThriftHelper.newRowMutation("test-table", "row-123", rm1, rm2, rm3); Record r = BlurThriftHelper.newRecord("test-family", "record-2", BlurThriftHelper.newColumn("g", "h")); Record r2 = BlurThriftHelper.newRecord("test-family", "record-99", BlurThriftHelper.newColumn("g", "h")); assertEquals("should find record-2", rm2, BlurThriftHelper.findRecordMutation(row, r)); assertNull("should not find record-99", BlurThriftHelper.findRecordMutation(row, r2)); }