The dumpOplog function in ReplSetTest prints out the oplog of a given node by iterating over each element in a cursor on that node's oplog. Since it makes a separate print call for each oplog entry, the output can get interleaved with other log messages, making it harder to read the oplog entries in order. We should improve this by building up a JSON string of all the oplog entries first, and then printing it with one call to jsTestLog.